INDUSTRIAL POLLUTION IN GHANA: SOME SELECTED CASE STUDIES OF INDUSTRIES IN TEMA A THESIS SUBMITTED TO THE UNIVERSITY OF GHANA IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGRJEE OF * MASTER OF PHILOSOPHY IN CHEMISTRY BY NORA PRISCILLA AMA KUMA TAYLOR B.Sc. (GHANA), PGCE (CAPE COAST) DEPARTMENT OF CHEMISTRY UNIVERSITY OF GHANA LEGON SEPTEMBER, 1999 University of Ghana http://ugspace.ug.edu.gh Dedication To my husband Nii, my children Richardar, Marguerita, Priscilla (Ranti). Margaret, Richard Emest(OB) and above all to the Glory o f the Living God who has made us to be Winners in all things. • f. ii University of Ghana http://ugspace.ug.edu.gh 6 f 3 6 0 S 1 7 TD I93*T ai University of Ghana http://ugspace.ug.edu.gh DECLARATION It is hereby declared that the thesis is my original work, done under supervision, and has not been presented wholly or partly for another degree in this university or any other university elsewhere. Nora P. A. K. Taylor (Mrs.) (Student) Dr. C. K. Akpabli, (Supervisor) (Supervisor) Mr. C. A. Biney, (Supervisor) Water Research Institute, CSIR. HI University of Ghana http://ugspace.ug.edu.gh ACKNOWLEDGMENTS This work has been made possible by the contribution o f a lot of people and it will be impossible to acknowledge all o f them. I wish therefore to extend my heart-felt thanks to all and sundry for the various roles they played. However, I want to acknowledge the following: My most sincere thanks go first o f all to Dr. C. K. Akpabli, my principal supervisor who directed me in all that I did. I also want to thank Prof. M. Dakubu and Mr. C. A. Biney, who did so much for me during the work. I wish to recognize the encouragement of the other lecturers in the Department. My gratitude also goes to the Management and the staff o f the following Establishments: a) Water Research Institute, especially the workers in the Water Quality Lab. who were more than brothers and sisters to me; b) Industrial Research Institute, especially Mr. E. F. Breuya and Dr. R. B. Lartey, e) Soil Research Institute especially, Mr. Emmanuel Akuffo; d) Tsma Oil Refinery particularly, Katherine Asante-Poku and Mr. Maxwell Anane; e) Tuyee Manufacturing Company especially, the Engineer, f) Cocoa Processing Company especially, Mr. Dwamena; g) Tenia Lube Oil Company especially, Mr. Asumang; h) Pioneer Food Cannery Ltd; i) Bridaltrust Paints Company Limited especially, Messieurs Akpetey and Ankrah; j) Ghana Textiles Manufacturing Company especially, Mr. Lokko; k) Ghana Textiles Printing Co. especially, Mi'. Obuamah. University of Ghana http://ugspace.ug.edu.gh T also wish to thank Dr. P. C. Acquah, the Executive Director, Messieurs Adu-Kumi and Lamhert all o f Environmental Protection Agency for the diverse contributions they made. To my colleagues on the M. Phil. Chemistry and Biochemistry Programmes, namely S. A. B. Aidoo, Antwi Aning, Christian Debrah, Dei Kaka, E. K. Oppong, Jeny Asiedu-Larbi, Anane Asare, Yawson and Asmah, I say thank you very much and God bless you. I wish also to express my sincere thanks to the Association o f African Universities (AAU) for a research grant that made it possible for me to do the work without any financial stress. Finally, my sheerest gratitude goes to the 'Wisdom and Power’ o f God, Christ the Living Saviour. Halleluia!! University of Ghana http://ugspace.ug.edu.gh 1. WIIO - World Health Organization; 2. AO AC - Official Methods o f Association o f Official Analytical Chemists ; 3. APHA - The American Public Health Association; 4. TOR - Tema Oil Refinery; 5. TMC - Tuyee Manufacturing Industries; 6 . CPC - Cocoa Processing Company; 7. TLC - Tema Lube Oil Company Limited; 8 . PFC - Pioneer Food Cannery Limited; 9. BPC - Bridaltrust Paints Company Limited; 10. GTMC - Ghana Textiles Manufacturing Company; 11. GTP - Ghana Textiles Printing Company Limited. LIST OF ACRONYMS vi University of Ghana http://ugspace.ug.edu.gh TABLE OF CONTENTS DEDICATION DECLARATION ACKNOWLEDGEMENTS ACRONYMS TABLE OF CONTENTS LIST FIGURES LIST OF TABLES ABSTRACT CHAPTER ONE INTRODUCTION AND LITERATURE REVIEW 1.1 POLLUTION 1.1.1 TYPES OF POLLUTION 1.1.2 EFFECTS OF POLLUTION ON WATER BODIES 1.2 INDUSTRIAL POLLUTION OF THE ENVIRONMENT 1.2.1 INDUSTRIAL POLLUTION OF WATER BODIES 1.2.2 IMPORTANCE OF WATER 1.2.3 PURITY OF WATER AND NATURAL PURIFICATION OF WATER BODIES 1.2.4 WATER POLLUTION AND LIVING ORGANISMS 1.3 POLLUTION DUE TO MANUFACTURING INDUSTRIES IN GHANA 1.3.1 TEXTILE INDUSTRY 1.3.2 PETROLEUM INDUSTRY 1.3.3 AGRO-BASED INDUSTRY 1.3.4 WASTE DISPOSAL AND TREATMENT 1.4 WATER POLLUTION INDICATORS AND METHODS OF DETERMINATION 1.4.1 PHYSICAL PARAMETERS 1.4.2 CHEMTC AT, PAR AMETERS 1.4.3 NUTRIENTS ii iii iv vi vii x xi xii 1 2 4 4 6 Qu 9 10 12 13 14 14 15 16 16 17 17 vii University of Ghana http://ugspace.ug.edu.gh 1.4.4 MAJOR TONS ... 18 1.4.5 TRACE METALS ... 19 1.5 TREATMENT OF INDUSTRIAL EFFLUENTS ... 2 2 1.5.1 PRIMARY TREATMENT ... 23 1.5.2 SECONDARY TREATMENT ... 24 1.5.3 TERTIARY TREATMENT ... 25 1 . 6 WORK DONE ON INDUSTRIAL POLLUTION IN GHANA ... 26 1.7 OBJECTIVE OF PRESENT WORK ... 27 CHAPTER TWO METHODOLOGY 2 , 1 SAMPLING OF WASTEWATERS ... 31 2 .1 . 1 INDUSTRIES SAMPLED ... 31 2 . 2 DETERMINATION OF PARAMETERS ... 35 2 .2 . 1 PHYSICAL PARAMETERS ... 35 2 .2 . 2 CHEMICAL PARAMETERS ... 36 2.2.3 NUTRIENTS ... 38 2.2.4 MAJOR IONS ... 39 2.2.5 TRACE METALS ... 41 2.3 LABORATORY TREATMENT OF THE WASTEWATERS ... 43 2.3.1 MATERIALS AND PREPARATION OF MATERIALS ... 43 2.3.2 TREATMENT OF WASTEWATERS 44 2.3.2.1 AEROBIC TREATMENT ... 45 23.2.2 ANAEROBIC TREATMENT ... 45 23.2.3 SAND FILTRATION ... 45 2.3.2.4 PAPER FILTRATION ... 46 23.2.5 CHEMICAL COAGULATION & SEDIMENTATION ... 47 23.2.6 ACTIVATED CHARCOAL TREATMENT ... 47 23.2.7 PALM KERNEL AND COCONUT HUSKS CHARCOALS TREATMENTS ... 47 2.3.2.S SOIL TREATMENT viii ... 47 University of Ghana http://ugspace.ug.edu.gh CHAPTER THREE RESULTS AND DTSCIJSSTON 3.1 RAW EFFLUENTS ... 49 3.1.1 PHYSICAL PARAMETERS ... 57 3.1.2 CHEMICAL PARAMETERS ... 62 3.1.3 TOTAL DISSOLVED SOLIDS AND TOTAL SUSPENDED SOLIDS , ... 64 3.1.4 NUTRIENTS ... 6 6 3.1.5 MAJOR IONS ... 67 3.1.6 TRACE METALS ... 69 3.2 LABORATORY TREATED EFFLUENTS ... 74 3.2.1 AEROBIC TREATMENT ... 84 3.2.2 ANAEROBIC TREATMENT ... 93 3.2.3 FILTRATION METHODS ... 94 3.2.4 CHEMICAL COAGULATION ... 96 3.2.5 OTHER METHODS OF TREATMENT ... 96 3.2.6 TRACE METAL REDUCTION ... 97 CHAPTER FOUR CONCLUSION 4.1 INDUSTRIAL WASTEWATER EFFLUENTS AND POLLUTION ... 100 4.2 RECOVERY OF USEFUL WATER FROM INDUSTRIAL WASTEWATER EFFLUENTS ... 101 4.3 RECOMMENDATIONS ... 102 REFERENCES ... 103 APPENDICES: I MAP OF TEMA SHOWING THE INDUSTRIES SAMPLED ... 109 n CALLBBRATION CURVES FOR SOME PARAMETERS ... 110 IH GRAPHICAL PRESENTATION OF PARAMETERS ix University of Ghana http://ugspace.ug.edu.gh LIST OF FIGURES Fig. 1 MAP OF TEMA SHOWING THE INDUSTRIES SAMPLED . . . 103 Fig. 2 PREPARATION OF DOTTLE FOR SAND FILTRATION ... 46 Fig. 28 % CHANGE OF BOD WITH TREATMENT (TLC) ... 85 FIG. 29 % CHANGE OF BOD WITH TREATMENT (PFC) ... 85 FIG. 30 % CHANGE OF BOD WITH TREATMENT (GTMC) ... 8 6 FIG. 31 % CHANGE OF TURBIDITY WITH TREATMENT (TLC) ... 8 6 FIG. 32 % CHANGE OF TURBIDITY WITH TREATMENT (PFC) cmO f FIG. 33 % CHANGE OF TURBIDITY WITH TREATMENT (GTMC) ... 87 FIG. 34 % CHANGE OF P 0 4-P WITH TREATMENT (TLC) . . . 89 FIG. 35 % CHANGE OF P 0 4-P WITH TREATMENT (PFC) . . . 90 FIG. 36 % CHANGE OF P 0 4-P WITH TREATMENT (GTMC) . . . 90 FIG. 37 % CHANGE OF NQj-N WITH TREATMENT (TLC) ... 91 FIG. 38 % CHANGE OF NO 3-N WITH TREATMENT (PFC) ... 92 FIG. 39 % CHANGE OF N 03-N WITH TREATMENT (GTMC) ... 92 X University of Ghana http://ugspace.ug.edu.gh LIST OF TABLES TABLE 1 INDUSTRY, PRODUCTS AND CATEGORY OF WASTEWATER TABLE 2 PHYSICAL AND CHEMICAL PARAMETERS - MEAN VALUES TABLE 3 NUTRIENTS AND MAJOR IONS - MEAN VALUES TABLE 4 MEAN CONCENTRATION OF TRACE METALS TABLE 5 MEAN AND RANGE VALUES FOR ALL INDUSTRIES COMPARED WITH WHO AND EPA LIMITS TABLE 6 DIFFERENCES IN THE LEVELS OF POLLUTANTS IN THE WASTEWATER AND THE SEAWATER RESERVOIR AT TOR TABLE 7 THERMAL ACTIVATION OF SOILS TABLE 8 PHYSICAL CHARACTERISTICS, K AND P CONTENTS OF SOILS TABLE 9 SOME PHYSICAL, CHEMICAL PARAMETERS AND NUTRIENT LEVELS BEFORE AND AFTER TREATMENT - TLC TABLE 10 SOME PHYSICAL, CHEMICAL PARAMETERS AND NUTRIENT LEVELS BEFORE AND AFTER TREATMENT - PFC TABLE 11 SOME PHYSICAL, CHEMICAL PARAMETERS AND NUTRIENT LEVELS BEFORE AND AFTER TREATMENT - GTMC TABLE 12 MEAN CONCENTRATION OF TRACE METALS BEFORE AND AFTER TREATMENT - TLC TABLE 13 AVERAGE LEVELS OF TRACE METALS BEFORE AND AFTER TREATMENT WITH SOILS - TLC TABLE 14 % CHANGE IN VALUES OF WASTEWATER PARAMETERS AFTER TREATMENT - TLC TABLE 15 % CHANGE IN VALUES OF WASTEWATER PARAMETERS AFTER TREATMENT - PFC TABLE 16 % CHANGE IN VALUES OF WASTEWATER PARAMETERS AFTER TREATMENT - GTMC 50 51 52 53 55 75 75 76 77 32 79 ... SO 81 . . 82 O'?o3 XI University of Ghana http://ugspace.ug.edu.gh Abstract Waste waters from eight selected industries namely Tema Oil Refinery, Tuyee Manufacturing Industries, Cocoa Processing Company, Tema Lube Oil Company Limited, Pioneer Food Cannery Limited, Bridaltrust Paints Company Limited, Ghana Textiles Manufacturing Company and Ghana Textiles Printing Company Limited were sampled and subjected to various physico-chemical and trace metal analysis to determine levels of pollutants, using standard methods o f WHO, AO AC and APHA. Generally, the ROD values were found to be high for all the industries. Some other parameter levels were significantly high enough for the individual industries to deserve attention. Generally, the results seem to suggest that these industries sited in Tema, are likely contributors to the high degree of" pollution of the Chemu n and Gao Lagoons which have been reported by various workers as being highly polluted. Consequent to the results obtained, an attempt was made to treat the wastewaters. Thus wastewaters o f three of these major industries Ghana Textiles Manufacturing Company. Pioneer Food Cannery Company Limited and Tema Lube Oil Company Limited, representing the textile, food and petroleum-based industries in the Tema industrial area o f Ghana were subjected to various physical and chemical treatments using mainly local materials, to try and reduce the levels of pollutants detected in the earlier investigations. Sedimentation, filtration using paper and sea-sand and adsorption using charcoals prepared from dried coconut husks and palm kernel husks as well as industrially prepared activated charcoal as adsorbents, were some o f the physical methods used whilst chemical precipitation and oxidation-reduction were the chemical methods used to bring about the desired results. Six different naturally occurring soil samples from Ankaful, Ekon and Elmina in the Central Region, Asokwa in the Ashanti Region, Bokazo in the University of Ghana http://ugspace.ug.edu.gh Western Region and Somanya in the Eastern Region were also used to obtain some levels of purification and the results compared. Most o f the methods decreased the levels of pollutants determined in the earlier investigations. Biochemical Oxygen Demand, nitrate, phosphate, conductivity, turbidity and colour of the waste waters were brought significantly to the acceptable limits o f World Health Organization and Environmental Protection Agency and trace metals were reduced, in some cases to below detectable limits making the waters safe for re-use domestically and industrially. Sand filtration stood out as die single best method for the treatment o f the wastewaters. The easy availability and affordability of sand coupled with the simplicity of its use in filtration should make it a convenient method for the treatment of impure water on a small scale in industry as well as in homes and farmsteads University of Ghana http://ugspace.ug.edu.gh CHAPTER ONE INTRODUCTION AND LITERATURE REVIEW 1.1 POLLUTION Pollution is as old as civilization and it is one o f its surest consequences. 1 ,2 Among the many environmental problems threatening man today, pollution arouses most interest because it impacts directly on man through effects on his food supply, health, buildings and other items o f cultural heritage as well as overt effects on forests, rivers, coastlines and familiar ecosystems. Pollution, being one of the most serious of all environmental problems, therefore poses a major threat to the health and well being of millions o f people and the global ecosystems. 3 ,4 The effect of pollution is insidious and most o f the harmful effects only become apparent after long periods o f exposure wliich most people are not aware of . 3 '6 It is therefore imperative that attempts be made to control, if not completely prevent pollution. It is estimated that presently, there are about 6 x 10^ chemicals that have been introduced into the environment (and these days about 1 0 0 0 are introduced eveiy year) o f which between 66.000 and 95,000 are currently in use commercially. 3 According to Kirkwood and Longley7, 100.000 chemical substances are in use in Europe today. According to the FAO, UN and UNESCO, “ Environmental pollution is the introduction by man of substances or energy, indirectly or directly into the environment wliich results in such deleterious effects as harm to living resources and hazards to human health, hindrance to marine activities including fishing, impairment of quality for use o f sea water and reduction of l University of Ghana http://ugspace.ug.edu.gh amenities. ” 8 Royal Commission on Environmental Pollution has another definition for it. To the Commission, “Pollution is the introduction by man into the environment o f substances or energy liable to cause hazards to human health, harm to living resources and ecological systems, damage to structure or amenity; or interference with the legitimate uses o f the environment.”' El-PIinnawi and Hashmi9 also echo this definition. Global warming, climatic change and the loss of biodiversity through the extinction o f many species may be wholly or partly due to environmental pollution. 3 The main factors responsible for pollution and other types o f environmental deterioration in any community or society may be due to the combined effects o f population, amuence and technology. 10 Basically, the larger the population, the greater the extent o f environmental deterioration due to related needs for food production, living space, waste disposal, communications and so on. Environmental pressures can therefore increase due to population growth and the expectation of higher living standards. 3 Pollution problems increase in severity when the rate of pollutant emission exceeds the capacity o f the environment to assimilate the pollutants. To control pollution therefore, there is a need to look at all these contributory factors carefully to assess their individual contributions and then plan short-term, medium-tenn and long-term strategies to combat the problem o f environmental pollution. 1.1.1 TYPES OF POLLUTION When gaseous, liquid or particulate wastes are introduced into the environment at such a rate that tiie environment cannot undergo self-purification, then the environment is said to be University of Ghana http://ugspace.ug.edu.gh polluted. Pollution can be classified according to the part of the environment that is affected. Pollutants can be natural or man-made, originating from domestic, agricultural or industrial activities and can end up in the environment, which comprises air, water and land, causing the environmental problems. There is therefore air pollution, land pollution and water pollution. Land pollution comprises o f pollution of soil and the animals and plants (fauna and flora) that inhabit it. The soil is the environment that is usually the first to be polluted by the various types of pollutants. 11 Water pollution involves all the water bodies like the sea, rivers, lakes and wells, which may be polluted with raw sewage, factory wastes, laundiy detergents and insecticide residues from agriculture which are introduced through various activities o f man . 5 Substances that cause pollution and are o f natural origin include radioactive fall-out which pollutes the air and can also be introduced into surface and ground waters as well as vegetation. Other substances are minerals, decaying bodies of animals or plants and disease-causing organisms. 6 ,8 Man-made pollutants are as varied as the human or anthropogenic activities that produce them . 6 ,8 Domestic, agricultural and industrial types are usually identified. In rural areas, where sanitary safeguards are lacking, pollution is mostly domestic which is mainly from garbage and excreta2 ,6 whilst in urban areas, there are the industrial sources of pollution to contend with, in addition to the domestic source. 3 University of Ghana http://ugspace.ug.edu.gh Pollution can also be classified as intentional or unintentional. For example, in the quest for increase in food output, a farmer may spray his crop fields with insecticides purposely to Mil harmful organisms, but this could also result in pollution, if the chemicals get into the environment. Such pollution is termed unintentional. With regards to intentional pollution, the offender is very much aware of the polluting potential o f his actions but all the same goes ahead to do them. 1.1.2 EFFECTS OF POLLUTION ON WATER BODIES The impact of industrial water pollution depends on the specific industry discharges and the assimilative capacity of the water body for the effluents being discharged. 4 H ie introduction of wastewaters into water bodies may alter their natural state by changing their pi I, conductivity, dissolved oxygen, 6 colour11 and so on, thus, malting the water unhealthy. It can also introduce particulate matter and trace metals into the water bodies and can destroy the aesthetic beauty of the water bodies. This interferes with the use of the water for not only domestic purposes but also recreational activities like boating and swimming. 1.2 INDUSTRIAL POLLUTION OF THE ENVIRONMENT With increases in population leading to aggregation into larger communities and the expansion in socialization, human needs also expanded and became more diverse. Subsequently, there arose the need to look for other avenues apart from the natural provisions, to satisfy these needs and this led to the establishment o f industries. Industries came to be established to provide goods and services needed for human development and comfort. Crop farming, animal 4 University of Ghana http://ugspace.ug.edu.gh farming, f ish in g lumbering, manufacturing and other industries are now well developed to provide man's complex needs. Hie varied nature of the products and services provided by the industries requires that they use a diverse array of raw materials and methods in production which give rise to different types of wastes, which have to be disposed of. With modem civilization, wastes are generated by virtually eveiy manufacturing industrial enterprise. These wastes of industrial origin can be gaseous, liquid or solid. For example, a pharmaceutical industry generates waste solvents when purifying ethical drugs and discarding products or raw7 materials that do not meet specifications. Large amounts o f solid w'aste is produced in industries like the textile and food industries where remnants o f yam, dye-stuSs and left-over foods are produced in addition to large amounts o f hot water that contain other materials. A wide variety o f chemicals and other contaminants, some o f which are left-overs o f raw materials used in the production, thus form part o f the effluents from the modem manufacturing industries. There is no doubt that at present, the most severe form of pollution in any settlement is the direct result of man’s activities. 5 University of Ghana http://ugspace.ug.edu.gh Here in Ghana, gaseous wastes are mainly produced by industries like Ghana Cement Company Limited(GHACEM), liquid petroleum gas (LPG) filling depots, aluminium production from bauxite, burning o f unused fossil fuel during refineiy operations and in the production o f other manufactured goods whose production processes involve combustion, such as the brick and tile industries. 1.2.1 INDUSTRIAL POLLUTION OF WATER BODIES From the earliest times, humankind has introduced undesirable substances itrio the very sources from which he obtains water for domestic and other uses as shown by archaeological evidence that the earliest civilizations relied partly on waterways for waste disposal. 1 ,12 Water bodies had been considered big sinks in which the undesirable materials could be deposited3 and the waterways were receiving and carrying away the wastes of people living near them . 1’12 ,13 Thus industries have been generally, conveniently sited near sources of water not only for the reason already stated, but they have been used for the disposal o f wastes as well3 4 3 The manufacturing industries sited near sources o f water obtain water readily and cheaply for washing, cleaning or cooling in the course o f manufacturing various products. Water is also sometimes used to dilute waste products to an acceptable concentration before returning them to the receiving waters. 14 Liquid wastes can be introduced directly into the water bodies, whilst gaseous ones are dissolved by rainwater which is a powerful solvent or by dry deposition and introduced into water bodies, and through leaching pollutants from solid wastes can also be introduced into 6 University of Ghana http://ugspace.ug.edu.gh water. No matter the sort of waste produced therefore, the final destination of the waste is the ground and surface waters. Industries in general use veiy large quantities of water but very little o f it is incorporated into the products, particularly in food and beverage industries. Cooling, washing and steam raising usually account for up to 85% of the total water requirements o f industries. Almost all the used water is discharged carrying varying amounts of waste substances11 such as chemicals. 2 Loss of water quality o f the receiving water bodies may be due to enrichment, that is eutrophication, with degradable organic materials including effluents from the food or other industries, crop farms or fish farms. In addition, the leaching of minerals such as nitrogen compounds, phosphate and potash from agricultural lands or from other sources like agro-based industries can lead to the development o f algai blooms in water which can further lead to secondary BOD increases or loads. Even though industrial effluents disposal, in the form of direct liquid and solid wastes dumping into water bodies4 as well as indiscriminate hazardous waste disposal is a growing problem for both surface and groundwater pollution, municipal wastes is by and large the largest contributor of the pollutants of water. 4 ,13 Whilst the municipal wastes are mostly composed o f easily decomposable organic materials, industrial wastes can contain highly toxic materials. According to a study of the sources of industrial pollution made by LTNEDO between the coast of T .a Cote d'Ivoire and Renin, the main producers of industrial pollutants by weight is the 7 University of Ghana http://ugspace.ug.edu.gh textile industry whose wastes contain 30% of all polluting substances, 25% from the food industry, 2 0 % from petroleum industries and about 1 0% from mineral exploitation and processing. However in Accra, there are seven times more food production factories than textile factories, wliich are mostly involved in cutting and sewing, hi Ghana, there is only one refinery (TOR) and one major petroleum-based industry, Tema Lube Oil Company which are situated in Tema, in the Sakumo II catchment area. Pollution from manufacturing and processing industries are however mainly localized. 2 Korle, Chemu and Mokwe Lagoons, which are located in industrial areas in Accra, have been reported variously by Aimuzu, Biney and GEMS to be highly polluted. The Chemu I -agonn, confirmed as being highly polluted, 13 is located in the industrial zone o f Tema Municipal Area and thus is fed with a lot o f wastes including liquid wastes in the form o f wastewaters from the industries that are situated there. It is rather unfortunate, that though wastes can be treated to reduce the pollutant levels' 5 1 6 and possibly to retrieve some useful materials from them, even large, well-established industries in Ghana and other countries like Nigeria2 ’4 lack the infrastructure for their treatment. 1.2.2 IMPORTANCE OF WATER Living things, including man are composed of cells that contain at least 60% of water12 ,13 Apart from water intake to maintain this level, they also use water externally. Organisms can therefore exist and thrive only where there is adequate supply of water. Over 70% of the earth’s crust is covered by water, the bulk of which is seawater. 17 Water is our most precious mineral and University of Ghana http://ugspace.ug.edu.gh from the beginning o f history, it has been the key to and focus for civilization and development. 12 Water has also been the largest contributory factor in the growth o f populations into famous cities. No settlement, whether big or small, can survive without potable water. The need for other necessities like food, clothing and shelter, among others, cannot be met without an adequate supply o f water. However, to be suitable for human consumption, water should be substantially free of impurities and bacterial contamination. i .2.3 PURITY OF WATER AND NATURAL PURIFICATION All waters may show some characteristics o f pollution - be it natural or industrial. In many cases, both natural and industrial pollutions are involved, even though the latter is of main concern these days. Seas, rivers, lakes and streams are natural bodies o f water that are sources of food and water which are very necessary for the survival o f living organisms. These may be altered considerably by ‘natural pollution’ from sources like radioactive fail-out and biological material decay. Rivers and streams are more often large is of pollution. Many of the important qualities in which natural rivers differ from one another, such as the type o f substratum, amount o f silt, oxygen content, acidity, alkalinity, hardness and temperature arc just those that arc altered by most types of pollution. The main effects of pollution are to some extent transitory', and if they are not too severe, and if the river is long enough and receives enough extra water from tributaries and surface run-off, it can re-purify itself. With the less persistent effects, such as de-oxygenation, suspended soEds, or increase in temperature, the alteration may be detectable only for a mile or two below the effluent discharge point. But, usually the pollution is heavier 9 University of Ghana http://ugspace.ug.edu.gh than this and the alterations may persist for a long, long way and a long, long time. Therefore, a conscientious effort has to be made to clean up the environment by man himself since to a very large extent, he put those extra substances where they are not supposed to be. A liver that is made more silty, more acidic, more alkaline, less well-oxygenated, warmer, harder, saltier or richer in nutrient salts is still a natural water as long as the change is not so great as to overstep the boundaries of normal variability. This is true even in the case o f some poisons; in spite of the presence of small amounts in the water, it is still considered to be natural water. 3 ,14 Under natural conditions, flowing waters have powerful self-purifying mechanisms that include sedimentation and biochemical oxidation. 7 Naturally occurring micro-organisms decompose organic wastes and are in turn consumed by larger organisms and fish while aquatic plants in the presence o f sunlight help to restore the oxygen balance, a process that is aided by surface aeration. In most instances of water pollution, the extent is such that the natural purification becomes difficult or impossible. It is therefore necessary to avoid that extent of pollution by treating or cleaning the wastewaters before discharge into the water bodies. Industrial wastewater effluents affect the punty of the receiving water, in that both soluble and insoluble solid concentrations are increased which affect other parameters like conductivity, pH and so on. Harmful, disease-causing organisms can also be introduced through this channel. 1.2.4 WATER POLLUTION AND LIVING ORGANISMS Pollution of water could lead to contamination of aquatic life and loss o f aquatic life, both flora and fauna. 6 For example, some lakes are becoming increasingly polluted resulting in die death 10 University of Ghana http://ugspace.ug.edu.gh o f aquatic organisms like fish. 3 ’7 Pollutants such as trace metals that may accumulate via food webs in terrestrial or aquatic environments, cause toxic effects at the upper trophic levels of food webs to organisms.7>n The effects of trace metal pollution at higher trophic levels include delayed embryonic development, 12 malformation and reduced growdi o f adults o f fish, molluscs and crustaceans18 Some of these metals like Fe, Sn, V, Cr, Co, Mn, Ni, Zn and Cu are essential for metabolism at reasonably low concentrations but in high concentrations, they are toxic to organisms including man . 7,11 They can react with proteins, DNA and RNA affecting metabolic processes and react with other substances causing undesirable physiological changes. They can also cause enzyme inhibition by competing for sites on the substrates and thus change the rate o f catalyzed decomposition o f metabolites. 18 Some other metals like Pb, Ag and Hg which are normally present in relatively low concentrations in industrial wastewater effluents when ingested by humans and other animals may cause various physiological effects, although some o f them may not invoke any response at all. Some o f the trace metals like manganese and chromium are also mutagenic and carcinogenic. 5 ,1 9 There are also neurological conditions linked to Hg and Pb pollution. In the case of the latter, it is ubiquitous due to its use as an additive in petrol. The effects o f pollution may be biological as well as physical. At low concentrations, many heavy metals including Hg, Cu. Pb, As and Cu, inhibit photosynthesis and phytoplankton growth. In Ghana, the destruction of one-time important lagoons like Chemu and Korle has been attributed to the discharge o f untreated wastewaters into the water bodies. 20 Barely thirty years ago, the Korle. Lagoon was well-stocked with Tilapia and other useful aquatic organisms and some edible crabs crawled on its banks. Now, the water is without any Tilapia, the edible crabs 11 University of Ghana http://ugspace.ug.edu.gh are gone and die Lagoon has lost its economic value and aesthetic beauty because ol pollution. 21 The Korle Lagoon has been reported as being the most polluted coastal lagoon in Ghana. Water pollution may also arise as a result of increase in concentrations o f nutrients. For example, high levels of nitrate are hazardous to health and directly dangerous to infants. 13 Nitfosamines, formed via nitrate and nitiite, are carcinogenic at liigh concentrations o f more than 20 mg/L. Ammonium can also be poisonous as it forms NII3 which is toxic at high pH values22 and water with a high pH that contains high levels of NH)+ is toxic to fish. Discharged wastes may also contain disease-causing micro-organisms which when ingested directly into the body either through food or water can cause diseases like cholera and dysentery and also many intestinal diseases as occurred in the USA and Europe in the nineteenth and twentieth centuries ' Water in its non-sterile forms is responsible for 40 % o f medical diseases There is a significant decrease in the production o f viable human sperms in technologically advanced countries due to in part exposure to pollutants. 3 1.3 POLLUTION DUE TO MANUFACTURING INDUSTRIES IN GHANA In Ghana, the manufacturing industries are concentrated in Tema, the industrial city o f the countiy and Accra. However, Takoradi and Kumasi also have a fail1 share of industries. These industries produce a wide variety of goods, from petroleum-based products such as petrol through cement, textiles, paints to canned foods. Many industries dispose of their wastes, 12 University of Ghana http://ugspace.ug.edu.gh mainly in form o f liquid wastes, through their wastewaters, when water is used as a transport medium . 13 ,17 Although the volumes of wastewaters produced by these industries are low as compared to those of industrialized countries, the unregulated manner of disposal o f the wastes constitutes the problem. These wastes are commonly introduced directly without treatment into the water bodies especially surface ones. 4 '11 ' 15 hi an article captioned “Wuiet bodies under threat from industrial Pollution' in the 20th October, 1998 edition o f the Daily Graphic, 20 Dr. G. Manful, Director of Operations of the EPA stated that industries in the countiy discharge nearly 2 1 million cubic meters of wastewaters into the water bodies. 20 1.3.1 TEXTILE INDUSTRY The raw materials for the textile industry include cotton yam, dyestuffs, oxidizing and bleaching agents, silicates, inorganic salts and sodium hydroxide. Textile plants usually have a grey mill for the weaving of cloth and a finishing mill where the cloth is dyed, printed or embroidered. Solid wastes produced in the textile industry are mainly the remnants of yam and dyestuffs Large amounts o f hot water that contain dissolved and suspended materials, like chloride, sulphate, phosphate and peroxide form the liquid waste. Tt also contains toxic metals like copper, chromium, zinc, tin and iron and their ions form the liquid waste. The effluents of the textile industries couid also be contaminated with oils, greases and waxes that come mostly from the finishing mill. The dyeing process is the most hazardous, contributing trace metals like Cr, Pb, Zn, and Cu to wastewaters. 24 13 University of Ghana http://ugspace.ug.edu.gh 1.3.2 PETROLEUM INDUSTRY The main raw material for the petroleum-based industries is petroleum which is a fossil fuel and can contain trace metals like Cd, Co, Ni, Se, B, Bi in addition to nutrients like nitrates, sulphates, nitrites and ammonia. 25 Tn his hook 'Chemical Principles of Environmental Pollution’, Alloway26 stated that fossil fuels contain a wide range o f heavy metals and the combustion o f these fuels can release Cd, Zn, As, Sb, Se, Ba, Cu, Mn and V in addition to Pb into the environment. Production of petrol, kerosine among other products, is mainly by fractional distillation and since this involves cooling, a lot o f hot water is also produced which can increase the temperature of the receiving waters.* This hot water can also contain dissolved and suspended solids like sulphur. However, the major pollutants from this industry are gaseous emissions of sulphur, nitrogen and oxides o f carbon and hydrocarbons like methane (CH4 ), ethane which through dissolution can enter into surface and ground waters. 2 ,9 Particulate materials, aldehydes, NH3 and organic acids can be present too. Other waste substances that are likely to be present in the wastewaters from this industry are oil and grease and organic acids. 4,25 1.3.3 AGRO BASED INDUSTRY Hie raw materials of agro-based industries are diverse and depend 0 1 1 the particular industry involved. They include crops like tomatoes, onions and pepper, farm-reared animals like sheep and goats, fish from inland and coastal waters. From this diverse array o f materials, processing is done to obtain a wide variety of manufactured goods. In the agro-based industries, the effluents are mainly organic with some amounts of nutrients like nitrate, orthophosphate and 14 University of Ghana http://ugspace.ug.edu.gh sulphate. 9 Depending upon the particular industry and raw materials used, other pollutants may be present. Although this group o f industries is very diverse, all dispose of large amounts of organic wastes creating BOD, suspended solid, turbidiiy and pH problems. 4 2 3 13,4 WASTE DISPOSAL AND TREATMENT Archaeological evidence shows that the earliest civilizations relied on at least three strategies to combat the problem of waste accumulation. Firstly, there were centralized rubbish piles that contained diverse wastes including industrial wastes in addition to human waste, secondly by nomadic life maintenance, a system in which population was low and waste disposal was spread over a large area and thirdly waterways were receiving and carrying away the waste o f people living near them . 1 There are currently three main ways o f waste disposal; landfill, water-bome disposal with eventual drainage out to the sea and thirdly, dispersal o f the waste to the atmosphere. Solid wastes are used in landfills whilst gases are introduced high into the atmosphere through long chimneys. 16 Industrial wastewaters are commonly introduced into water bodies especially surface ones4 but can also get into contact with land and vegetation through leaks in gutters and pipelines. As far as land is concerned, the soils have the capacity for adsorbing and filtering off most of the polluting organic, inorganic and trace metals so that the levels are reduced before they leach or permeate into ground water. By and large, the medium that is most affected by industrial wastewaters is surface water. 26 15 University of Ghana http://ugspace.ug.edu.gh 1.4 WATER POLLUTION INDICATORS AND METHODS OF DETERMINATION Virtually all analytical techniques may have been used for the manual analysis o f water, 27 though at present only few find common application. Although there are numerous methods available for the determination of the various parameters to be measured, only a few will be reviewed. The methods that will be discussed include chemical, titrimetric, gravimetric and instrumental methods or combinations of them. The instrumental methods involve those in which instruments are used to directly read off the concentration of the analyte, whilst the chemical ones involve the conversion of the analyte into a new compound usually coloured that can be colorimetricaUy estimated. 1.4.1 PHYSICAL PARAMETERS Tlie physical parameters considered are temperature, pH, conductivity, dissolved oxygen, suspended solid3 and dissolved solids. Measurement o f the physical parameters has mostly been done by direct reading instruments. Temperature, pH, conductivity, dissolved oxygen and suspended solids can all be measured instrumentally by using mercuiy-in-glass thermometer, pH meter, conductivity meter and dissolved oxygen meter respectively. Dissolved oxygen can also be determined chemically by the Azide Method that is still veiy much used 2 8 It has also been determined by amperometric titration29 ’30 and coulometric titration31 Suspended solids and dissolved solids have also been determined gravimetrically32Jj by taking a known volume o f the wastewater and filtering it with a 45 urn filter. 34 The method is still veiy much used for these determinations. 16 University of Ghana http://ugspace.ug.edu.gh 1.4.2 CHEMICAL PARAMETERS The Biochemical Oxygen Demand (BOD) and Chemical oxygen demand (COD) are the chemical parameters discussed. Biochemical Oxygen Demand (BOD) measurement is by the Incubation Method that comes in varied forms. One such method, the Winkler's Azide Modification method involves the use of sodium azide. 3 2 There is another variation of the Azide method called the Pomeroy-Kirshman-Alsterberg Method3^ in which the weights o f NaOH, Nal and NaN3 are different from the Winkler one. lhere are modifications o f the above method in which potassium permanganate and potassium oxalate solutions are used instead of sodium azide. 34 Couiometric titration has also been used to determine BOD . 35 Chemical oxygen demand can be determined by the dichromatc and permanganale methods. 6 After refluxmg and cooling, the excess dichromate or permanganate can be determined by titrimctiy32 or colorimctrieally. Moore ct al36 and Jirka and Carter57, in 1949 and 1975 respectively, determined COD colorimetrieally after the refluxing with dichromate by reading the absorbance of the resulting solution at 600 nm. COD can be determined by potentiometric titration also. 35 1.4.3 NUTRIENTS Orthophosphate Orthophosphate can be determined by the ammonium molybdate method. 4 3 This method has a chcmical component as well as an instrumental component. The orthophosphate was reacted with vanodomotybdic acid in another method and the absorbance read at 440 nm . 27 Amuzu39 17 University of Ghana http://ugspace.ug.edu.gh in 1975, employed a method in which the phosphate was determined coionmetncaily. Orthophosphate can also be determined by ion chromatography. Nitrate Nitrate can also be determined by the bmcine-sulphanilic acid method '11 that involves colorimetry. The phenol disulphonie acid method is also useful in the determination o f nitrate, Kamphake et al42 and Fishman et al43 in 1967 and 1964 respectively, determined nitrate by an indirect method involving the reduction of the nitrate to nitrite. Chromotropic acid (4.5- dihydroxy-2 ,7-naphthalene disulphonie acid) is also used in another method o f nitrate determination. 27 Nitrate determination could be by ion chromatography also as was used by Mintah-Boateng in 1995.44 1.4.4 MAJOR IONS Potassium, sodium, calcium, magnesium, chloride and sulphate were the major ions measured and hence they are discussed here. Potassium, sodium calcium and magnesium can all be determined by flame photometry and atomic absorption spectroscopy .34 Sulphate can be determined by the turbidimetric method as outlined in Official Methods of AOAC . 34 Ihe method involves the precipitation o f BaS0 4 from the sulphate ions in the wastewaters reaction with BaCl2. Reading of the sulphate concentration was done directly using a spectrophotometer. In another method, BaCl^ was added in excess to ihc wastewater and the excess precipitated with methylthymol blue. 45 The concentration of the uncomplexed methylthymol blue was read at 460 nm and was proportional to the concentration of sulphate. Amuzu40 in 1976 determined sulphate indircctly by EDTA titration using Erioehromc Black T as indicator. 18 University of Ghana http://ugspace.ug.edu.gh Among the methods that can be used for chloride determination, the argentometric method and the mercuric chloride method that are titrimetric are commonly used. Potentiometric titration'’6, coulometric titration4* and conductometric titration32 which, is very useful in the determination of small quantities o f cliloride, have been employed. Chloride has also been determined by the displacement of the thiocyanate ion from mercuric thiocyanate complex in the presence of trivalent iron and the absorbance of the resulting solution read at 460 nm . 47 1.4.5 TRACE METALS Several methods have been used to determine trace metals in all sorts o f matrixes. 5 In early studies, gravimetric, volumetric and colorimetric techniques were used. The more common colorimetric methods involve formation of soluble complexes, chelates, wiih such organic compounds such as dilhizonc, o-phenanihroiine and ammonium pyrolidine diihiocarbamaie. For example, iron has been determined by gravimetric, iitrimetric and colorimetric methods. Both pyridine and orthophcnanthroline have long been used to colorimctrically determine iron (H) . 48 ,49 Potentiometric titration has also been used for metal determination. 50 Modem methods such as anodic stripping voltametry (ASV) and the use of ion-selective electrodes (ISE) based on electrochemical principles are also used . 5 Other methods of metal determination employ nuclear related techniques. These include proton-induced X-ray emission (PIXE), instrumental nuclear activation analysis (INAA), X-ray fluorescence (XRF) and inductively coupled mass spectroscopy (TCP-MS). Most o f these 19 University of Ghana http://ugspace.ug.edu.gh methods are however expensive, and only a few recent studies in Africa51 have reported using them. Practically all metals o f interest to the water chemist may be determined by molecular absorption spectroscopy but since die early 1960s, AAS has replaced most o f these methods . 54 In Africa by far the most common method for trace metal determination is AAS. The technique is well documented and current publications indicate that it is constantly being improved. 5 The AAS has variety o f techniques including flame atomic absorption spectrometry, graphite furnace atomic absorption spectrometry and hydride generation atomic absorption spectroscopy. The technique involves the conversion o f at least a part o f the sample into atomic vapour and measuring the absorbance o f this vapour at an appropriate wavelength characteristic of the trace metal to be measured. According to Beer-Lambert’s Law, A = Log lo/I = abc, where A is absorbance, lo is the intensify of the incident beam, I the intensity o f the transmitted beam, a is a constant that is characteristic of the particular system, b is the path length of the optical beam (which can be kept constant) and c is the concentration of the analyte. The absorbancc is dircctly proportional to the concentration of the analyte in the sample. By 20 University of Ghana http://ugspace.ug.edu.gh comparing the absorbance with those obtained for reference samples o f known concentrations under the same experimental conditions, the analyte’s concentration is evaluated. The AAS is generally composed of a light source of a hollow cathode lamp (HCL), an atomizer, a monocliromator, a photoelectric detector and a signal processor. Samples analyzed are usually in solution that is sprayed into the flame. For good and reliable results, the absorption should be between 20 % and 80 %, corresponding to absorbance of 0.10 and 0.70 respectively. Presently, the trend is towards the analysis of solid samples55 which allows for the circumvention of processes that otherwise would have introduced contamination which processes include dissolution and dilution. 5 Electrothermal AAS, one o f the most attractive methods for determining trace elements in biological samples, involves the use o f the solid sampling technique. The techniques o f AAS are subject to various interferences. When concomitant elements affect an alternation in those physical and chemical properties or processes that control the final population of neutral ground state atoms o f the sample in the absorption cell, interference with the analytical signal results. The various innovations of the AAS are Hydride GAAS which is employed in the analysis of elements that form volatile hydrides, that is, Hg, As, Se, Sb, Sn and others. 56 Analyte is simultaneously converted into its hydride by using sodium borohydride (NaBPii) or tin (II) chloride as reducing agent and separated from its matrix. In spite of the numerous setbacks o f AAS, some of which have been enumerated above, it has advantages over other methods. These include high sensitivity for a wide range of metals, 21 University of Ghana http://ugspace.ug.edu.gh including those that are difficult to determine by flame photometiy and its specificity. Also, the method is fast and only a small amount o f the sample is needed. Also, any metal can be determined in the presence of other metals and there are very few metals that cannot be so determined. Some of the metals that can be measured are Groups 1A and 1B, Cd, Cr, Cu, Fe, Pb, Mu, Ag and Zn . 34 Other methods that have been used for the trace metal determination are atomic emission spectroscopy, X-ray fluorescence, neutron activation analysis, differential pulse polarography, anodic stripping voltametry and isotope dilution mass spectrometry. All o f the above methods have detection limits in the nanogram range. 5 7 However, in this study, the flame atomic absorption spectroscopy was used. Inductively coupled plasma emission spectroscopy is rapidly becoming one of the most important techniques o f trace metal analysis. One distinct advantage of this method over atomic absorption is its capability o f multi-element analysis and the linearity o f its calibration curve over at least five orders of magnitude compared to two magnitudes for AAS . 5 Even though there are varied methods for the determinations, the choice o f methods was primarily based on the availability o f the chemicals, instruments and other logistics. 1.5 TREATMENT OF INDUSTRIAL EFFLUENTS In the olden days, when population and the level of human activities was low, not much water was used and hcncc no-onc eared about pure or impure water or purification o f water because nature did the purification on its own and that was enough. Nowadays, with an increase in 22 University of Ghana http://ugspace.ug.edu.gh population and a high demand for potable water, the natural purification alone is inadequate so there is a need to treat the wastewaters before discharging them into the water bodies. Before a wastewater can be treated successfully, the pollutants and their levels in the waste should be known19 and the nature of the wastewater, whether the pollutants are dissolved, colloidal or suspended and whether the pollutants are organic or inorganic, 13 so that the type of treatment the waste is subjected to, is related to the pollutants present otherwise, a lot of resources will be wasted on treatment without achieving any good results. The treatment o f wastewaters is usually in three stages classified as primary, secondary or tertiary. 17 ,58 i.5.1 PRIMARY TREATMENT This is physical3*55 and can also be referred to as mechanical. 13 The physical methods include phase separation which consists o f filtration and sedimentation and phase transfer which involves adsorption. Filtration and settling o f wastes remove larger particles by filtering through large screens and settling in ponds or lagoons. Water is removed from the top o f the pond and released. Water thus treated, has no sand or grit but still carries a heavy load o f dissolved organic matter, dissolved sails, bacteria and other micro-organisms. 58 The organisms use the organic material for food and as long as there is sufficient oxygen, they will continue to grow and rcproducc. I f the rccciving body of water is large or long enough and the organisms have enough time, the organic matter will be completely degraded. 6 23 University of Ghana http://ugspace.ug.edu.gh 1.5.2 SECONDARY TREATMENT This is mostly biological and usually follows the physical or primary method . 17 ,58 During anaerobic treatment, organic substances are broken down in the absence of oxygen to water, carbon dioxide and organic gases such as methane by micro-organisms/ ’0 ’1'5 In the presence and with addition of oxygen, the products are mainly water and carbon dioxide. With other organic substances such as fats, starches, proteins, amino acids, alcohols, cellulose and other substances o f varying degree of complexity, they are converted into ammonia (NH3), nitrate (NO3-N), phosphate (PO4-P), sulphate (S04) and carbon dioxide (C02) consuming large amounts of oxygen. 9 The wastewater is held until the organic material has been degraded by bacicria and other micro-organisms. To encourage this action, the wastewater is mixed with large quantities o f highly oxygenated water or the water is aerated directly as in the trickling filter system. In this proccss, the water is sprayed over the surface o f a column o f rocks and stones to increase the amount o f dissolved oxygen. The rock also provides a place for the bacteria and other microbes to attach so that they are exposed simultaneously to the organic matter and oxygen. These micro-organisms feed on the dissolved organic matter and small suspended particles which then become incorporated into their bodies as part o f the cell structure. 13 The bodies being larger than the dissolved organic and suspended matter, concentrate the organic wastes into particles that are large enough to settle ou t The sludge that settles therefore consists o f living and dead micro-organisms and their waste products. Another method, the activated sludge treatment involves some o f the sludge being returned to the aeration tanks, to be mixed with incoming wastewater. Like the trickling filter method, both produce sludge that settles out of water. The remaining sludge is concentrated and often dried 24 University of Ghana http://ugspace.ug.edu.gh before disposal. The disposal could be carried out in landfills, but some can be composted and returned to the land as fertilizer if not toxic. After complete oxygenation, heterophytic aerobic bacteria are replaced by anaerobic bacteria which can produce methane, hydrogen sulphide, ammonia (NH3 ) and iron (II) sulphide (FeS) 9 When wastewaters contain high levels o f organic solids, these can settle creating conditions that are liighly offensive to the eye and the nose. This is the first stage in the natural rectification or purification process. The primary and secondaiy* treatments are common in N. American countries. The wstsr discharged from these sewage treatment plants must be disinfected using the least costly method with chlorine or using ultrasonic energy to mechanically break down waste. The latter is less harmful and more effective but more expensive than chlorination. 17 1.5.3 TERTIARY TREATMENT This involves a variety of different techniques to remove dissolved pollutants left after the primary and secondary treatments. 17 The chcmical ones include acid-basc neutralization, chemical precipitation and oxidation and reduction. 3 These remove phosphorus and nitrogen, elements that increase aquatic plant growth. It is very costly because it requires specific chemical treatments of the wastewater to remove specific problematic materials. For example, hydroxyl ions (OH') are used to reduce or remove cations like Fe (II), Fe (Ht), A1 (HI), Hence, as far as tertiary treatment is concerned, industries have to maintain iheir own tertiary treatment facilities because o f the specific nature o f their waste products. 17 25 University of Ghana http://ugspace.ug.edu.gh The mechanical method removes settleable solids. It normally reduces the organic component o f the sewage by 30 %. This results by the phosphate present chemically combining with the suspended solids which when removed results in a decrease of the amount o f phosphates.1^ The biological methods involve the use o f micro-organisms to decompose and break down die organic pollutants under aerobic and anaerobic conditions. This decomposition process is extremely complex and consists of a long series o f sub-reactions with the process rate depending on many factors such as the oxygen content (DO), pH, temperature, type o f pollutants, the presence o f toxic substances, method of treatment and particle size. 1.6 WORK DONE ON INDUSTRIAL POLLUTION IN GHANA Some amount o f work has been done on the quality o f wastewaters from manufacturing industries but very little work has been done on treatment o f the wastewaters. Mititah-Boateng44 (1995) o f Water Resources Research Institute (now Water Research Institute) o f Council for Scientific and Industrial Research (CSIR) determined the quality of wastes including wastewaters from selected industries among which were Tema Oil Refinery and Unilever. Biney59 (1991) also worked on industrial effluents and found ihe wastewaters to have polluting potential. Amekor60 o f the EPA did work on the quality o f water in the Chemu Lagoon in 1995 in which he determined the level o f pollutants in some selected industries including Tema Oil Refinery, Ghana Textiles Printing, Tema Textiles Limited (now Ghana Textiles Manufacturing Co.), Unilever and Bridaltrust Paints. He also concluded that the 26 University of Ghana http://ugspace.ug.edu.gh effluents were quite polluting and had serious effects on the Chemu and Gao Lagoons. Bruce- Tagoe21 in 1996 worked on wastewaters from some selected industries in Accra, which empty their wastewaters into the Odaw River and Korle Lagoon. The study showed that the industries are potential contributors to the pollution of these water bodies. In all the industries investigated by Bruce-Tagoe, only Ghana Industrial Holding Company (GIHOC) Pharmaceuticals treat their wastewaters to some extent. Biologically, the wastewater is aerated first and then chemically, alum is added to it. To a large extent, the treatment is successful, reducing most of the parameters including BOD, COD and dissolved solids. In 1997, Togbe and Co . 61 in the University o f Ghana worked on the effluents o f Pepsi and Coca Cola companies which bottle soft drinks and are sugar-based industries and established that they are potentially polluting in BOD. Presently, Acheampong62 o f Ghana Standards Board and some other workers o f the EPA are monitoring the effluent quality of wastewaters o f selected industries in the industrial zone o f the Tema Municipality. 1.7 OBJECTIVE OF PRESENT WORK There is very little quantitative information on ihe exient of industrial pollution in Ghana, but what information is available point to the fact that, there is a glowing problem that threatens the life, health and well-being of particularly the workers in the industries and the whole nation. This is particularly so, taking into consideration the fact that facilities for the treatment and disposal of industrial wastewaters are rudimentary or non-existent. 2 Very few industries make 27 University of Ghana http://ugspace.ug.edu.gh an attempt to treat or dispose o f their wastes properly. This is gradually endangering the life of man, but in his quest for a better and more fulfilling life, he is constantly exploiting whatever materials are available to manufacture what he needs. It is unfortunate that though wastes can be treated to reduce pollutant levels, even large, well established industries have little or no infrastructure for the treatment of their wastes, especially liquid wastes and dump them directly into the environment without any prior treatment. The wastes can be processed to recover useful materials or treated to reduce their volume, toxicity, or mobility thus reducing their impact on human health and the environment. 16 To ensure the effective treatment o f wastewaters, the level o f treatment should be related to the degree of pollution expected in the wastewater source and the nature of the wastewater, whether the pollutants are dissolved, colloidal or suspended and whether the pollutants are organic or inorganic. 0 Hence, there is a need for information o f pollutant levels in wastewaters before an attempt is made to treat them. Treatment o f wastes is veiy costly and impacts negatively on the profits of industries and that is one reason most are reluctant to treat their wastes and simply release them into the environment. In a World Bank Report on Nigeria, water pollution was reported as having the second liighest potential for future negative impact on the GDP of Nigeria, a developing country, and this was estimated at US$1 billion annually that can also put 40 million people at risk. 4 This could well be repeated for Ghana, another developing country' but may be, not in the same proportions. Great conservation problems face humankind today with regards to the keeping of water bodies clean and maintaining adequate and qualitatively useful supplies o f this natural resource22 in 28 University of Ghana http://ugspace.ug.edu.gh view o f the rapid growth of population and the daily rise in the demand for water. The International Environmental Technology edition o f Nov./Dec. 1998, referred to a press release in which water was referred to as the most important raw material o f the 21st centuiy. It aiso pointed out that an attempt must be made to ensure that water sources remain unpolluted or is purified since this is a world-wide problem. Piti5’ reported that a third o f the world’s population lives in seriously water-short regions, mostly in developing countries. Within this group, 1 . 2 billion people do not have access to clean water. l ie also predicted that within the nest decade, another 1 billion may fall into this water-deficient categoiy, if measures are not taken to reverse the trend. The costs of the effects of pollution are the depreciation of resources, lost productivity and the increasing resources used in cleaning up or improving polluted environments including water. These are high and are increasingly occupying the attention of governments and politicians in technologically advanced countries3 as well as in developing countries like Ghana and Nigeria. 2 ’4 ,25 Quick and inexpensive ways o f treating the wastewaters are therefore necessary to make treatment of wastes attractive and less cumbersome to people, especially those in industry so that ihey can treat their wastewaters before dumping them in the environment or before reusing them for potable purposes. There is need now than ever before for the treatment o f wastes especially liquid wastes, in one way or the other before they are disposed off finally into the environment. 29 University of Ghana http://ugspace.ug.edu.gh In the present study, the industries were put into three groups, the textiies, food or agro-based and petroleum-based industries. To be able to do a good job on them, it is imperative that the raw materials they use, the methods o f production and other vital information be obtained so that die problem can be tackled right from its inception, since industrial pollution has the notorious property o f being cumulative and finally, producing disastrous effects that are either irreversible or expensive to abate. 11 To make wastewater treatment easier and cheaper will therefore be a very welcome and preferred thing indeed, since it will help industries to maximize their profits whilst also safeguarding the health o f the people and the environment at large. It is towards this end that this study was initiated to: a) determine the quality of various wastewaters from selected industries to ascertain the major pollutants and their levels; b) identify those industries that need to clean up or treat their wastewaters before their discharge into the receiving water bodies; c) investigate and find out other alternate and cheaper methods for wastewater treatment using local materials. 30 University of Ghana http://ugspace.ug.edu.gh CHAPTER TWO METHODOLOGY 2.1 SAMPLING OF WASTEWATERS 2.1.1 INDUSTRIES SAMPLED Requests to sample the wastewater effluents were sent to thirty' industrial companies but only nine industries responded favourably. Eight o f them were sampled, because although Unilever (Ghana) Limited responded favourably, permission could not be obtained for the sam p lin g to be done despite several visits to the factory. The industries sampled are all sited in the T ight and the Heavy Industrial Areas o f Tema. Their products and the nature o f their wastewaters are shown in Table 1. 31 University of Ghana http://ugspace.ug.edu.gh TABLE 1 INDUSTRIES, PRODUCTS AND CATEGORY OF WASTEWATER INDUSTRY ACRONYM/ NUMBER PRODUCTS CATEGORY OF POLLUTANTS Tema Oil Refinery TOR petrol, kerosine, liquid organic, colloidal and 1 petroleum gas (LPG). highly saline. Tuyee Manufacturing TMC industrial starch, writing chalk, organic waste, dense Co. 2 cement. and colloidal. Cocoa Processing Co CPC Cocoa powder, chocolate, cocoa slightly, viscous Ltd. 3 butter. colloidal. Tema Lube Oil Co. TLO / TLC petrol and diesel engine, organic waste. Ltd. 4 hydraulic and gear oils, lubricating oils. colloidal. Pioneer Food Cannery Co. Ltd PFC 5 canned fish. pinkish and colloidal. Bridaltrust Paints BPMC oil and emulsion paints. coloured, densely Manufacturing Co. 6 colloidal suspension. Ghana Textile GTMC printed textile materials. coloured colloidal Manufacturing Co. 7 suspension. Ghana Textile GTP printed textile materials. coloured colloidal Printing Co. Ltd r>0 suspension. 32 University of Ghana http://ugspace.ug.edu.gh 2.1.2 THE CHOICE OF PARAMETERS Parameters determined were limited by availability o f equipment and reagents, but as much as possible it was done in such a way' as to allow comprehensive, logical and coherent conclusions to be made. Parameters determined were: a. Physical - Temperature, pH, conductivity, dissolved oxygen, suspended solids, dissolved solid; b. Chemical - Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD); c. Nutrients - orthophosphate, nitrate; d. Msyor ions - sodium, potassium, calcium, magnesium, sulphate; c. Trace metals - Cu, Pb, Co, Zn, Al, Mn, Ni, Cr and Fe. 2.1.3 SAMPLE COLLECTION AND PRE-TREATMENT At each factory, the sampling was done at the end o f the production line, as the wastewaters issued out into the drains that cany' them into the Chemu Lagoon and appropriately labeled. At Tema Oil Refinery, a sample was collected from the Premier former cooling water observation point and labeled TORA. Oily petroleum fractions contained in this wastewater has been skimmed o ff by a mechanical process, after which the wastewater issued out into either the API or the Chemu Lagoon. At the API, by another mechanical device, an attempt is made to skim the oil o ff the top. The skimmed oily top that goes into the API was sampled and labeled TORB. When this oily wastewater had been passed through the APL it was collected and labeled TOR0. 33 University of Ghana http://ugspace.ug.edu.gh Cleaning of Sample Container Iligh density polythene containers were used because they suffer less from evaporation and adsorption- ion exchange problems.5 They are also less expensive and less fragile. The containers with well-fitting stoppers were pre-treated by washing with acetone to get rid o f organic substances, washing with detergent, rinsing with deionized water and steeping in 1.6 M nitric acid solution for between forty-eight hours to seventy-two hours.5 The containers were finally rinsed with de-ionized water and drained before use for holding the samples. Replicate samples were taken for each industry at every sampling. Attempts were made to sample at two weeks intervals but sometimes it was impossible to do so because personnel who should have accompanied the worker to the sampling points because o f security reasons were not available. Each industry was sampled at least on five different occasions. One Liter volume of each sample was taken. In order to avoid contact with air, which was necessary because pH and conductivity were to be determined, the sample containers were completely filled with the wastewaters.5,27 The wastewaters were collected into the pre-treated plastic bottles. Separate samples were collected for the field and laboratory measurements. Temperature, pH, conductivity and dissolved oxygen were determined at the sites immediately after sampling. The samples for other determinations were transported to the Water Quality Laboratory o f the Water Research Institute in ice-chest and kept under a temperature o f 4 °C and in ihe dark to prevent biological activity until they were needed for the remaining analysis.5 A third sample collected for metal determination, was acidified at the time o f collection by adding 2.0 mL o f conc. nitric acid per liter o f sample to reduce the pH to less than 2.32 For most trace metals like Fe, Cu, Ni, A1 and Zn, this ensures stability for several weeks. Biochemical Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) were determined within four and 34 University of Ghana http://ugspace.ug.edu.gh twenty-four hours after collection o f samples respectively.32 2.2 DETERMINATION OF PARAMETERS All the determinations o f the level o f pollutants were done by Standard Methods o f World Health Organization (WHO), the American Public Heallh Association (APHA) 3 2 and Official Methods o f the Association o f Official Analytical Chemists (A O A C f4 at the Water Resources Research Institute (CSIR). In the determination o f orthophosphate and trace metals standard solutions were used for plotting standardization curves. Treatment methods employed were as suggested by Ilynes3, Alloway6 and Kemi13. 2.2.1 PHYSICAL PARAMETERS Temperature, pH and conductivity were determined using a mercuiy-in-glass thermometer, a Gallenkamp pH meter with glass combination electrode and an Orion 120 conduciiviiy meter respectively, on the field immediately after sample collection. Buffer solutions of pH 4.0 and 10.0 provided by the manufacturer were measured with the pH meter before the actual measurements with the wastewaters were done. The conductivity meter was also used to measure standard solutions of potassium chloride (KC1) before its use to measure the conductivity o f the wastewaters. Total suspended solids was determined by a gravimetric method. 50.0 mL portions of the sample were filtered through pre-dried and pre-weighed 0.45 |jm millipore Watman filter papers. The filters with residues were dried in the oven to constant weight at 103 °C overnight and weighed again after cooling in a desiccator. 35 University of Ghana http://ugspace.ug.edu.gh The determination of total solids (TS) was done by taking 20.0 to 100 mL volumes o f the wastewaters in already weighed dry porcelain or glass dishes and heated over a water-bath until all the solvent water had evaporated. The dishes were then transferred to the oven and heated at a temperature o f 103 °C overnight to diyness. The dishes and their contents were then cooled in a dessicator and then weighed again. In the determination o f total dissolved solids, samples o f the wastewaters were filtered through 0.45 pm millipore filter and measured volumes o f either 50 or 100 mL of the filtrates taken in already weighed diy porcelain or glass dishes and heated over a water-bath until quite dry. The dishes with the residues were further dried in an oven at 103 °C overnight until a constant weight was obtained. 2.2.2 CHEMICAL PARAMETERS Dissolved Oxygen The narrow-necked, 300 mL BOD bottle was slowly and carefully filled with the wastewater sample to avoid trapping air bubbles. 2.0 mL each of manganese (II) sulphate and alkaline-azide-iodide solutions were added below the surface. The bottle was stoppered and inverted several times to mix the contents veiy well The preparation of the alkaline-azide-iodide solution is outlined in Appendix IV. A floe o f manganese hydroxides o f higher oxidation states was formed, which was allowed to settle. 2.0 mL of conc. H2S 0 4 was then added down the neck o f the bottle. The contents were mixed by inversion until iodine (I2) formed through a redox reaction between the manganese and iodide ions was uniformly distributed. 100.0 mL portions of the iodine solution were titrated immediately with a standard sodium thiosulphate solution using a starch indicator. The soultion was titrated with the 36 University of Ghana http://ugspace.ug.edu.gh thiosulphate solution until pale yellow before the starch solution was added. Biochemical Oxygen Demand The determination of biochemical oxygen demand was by Winkler’s Azide Modification Method. Two BOD bottles were filled with 250.0 mL of samples. To one was added 2.0 mL o f manganese (II) sulphate solution and 2.0 mL alkaline-azide-iodide solution prepared by dissolving specific weights of NaOH, Nal and Na azide as outlined in Appendix IV, was also added below the surface o f the wastewater. The bottle was stoppered, shaken well and allowed to stand. Floes o f manganese hydroxides o f higher oxidation states were formed. When the precipitates were about to settle, the bottle was shaken again Alter the floes have setfled, 2.0 mL of conc. H1SO4 was added down the neck of the bottle. The contents were mixed by inversion until iodine formed was uniformly distnbuted. The dissolved oxygen (DO) was determined as above. The other bottle containing only wastewater sample was incubated at 20 °C for five days and thereafter the DO was determined. A blank determination was doae using dilution water, prepared as in Appendix IV instead of die sample but treated in tiie same way as the incubated bottle. Equations of the Reactions Involved in Precipitation 1. Mn2+ + OH- p. Mn(OH ) 2 + 0 2 (from sample)-----p. Mn(OH ) 4 etc. 2. Mh(OH ) 4 + FT + T ^ I2 + Lower Hydroxides + H20 Equations o f the Reaction Involved in Titrimetry I2 + S2032' ►21' + S ^ - Chemic al Oxygen Demand The chemical oxygen demand was determined using the dichromate reflux method. 10.0 mL o f the 37 University of Ghana http://ugspace.ug.edu.gh sample, 1.0 mT, o f HgjSO,, (aq), 5.0 mL o f standard K 2Cr2Q7, 15.0 m l, Ag2S0 4 in H2S0 4 were put together and refluxed for 2 hours. After reflux, the contents o f the flask were cooled, diluted with de­ ionized water to 50.0 mL and titrated with standard ferrous ammonium sulphate solution using ferroin, an o-phenanthroline ferrous complex as indicator. The silver sulphate, Ag2S0 4 acts as catalyst, whilst Hg2S0 4 prevents chloride interference. After reflux, excess dichromate was titrated against standard ferrous ammonium sulphate and the COD measured as oxygen equivalent, proportional to the dichromate consumed during the reduction by the organic matter. The chemically oxidizable substances in the sample reduce Cr64 ions in K 2Q 2O7 to Cr+3. Equations of the Reaction Involved In Titrimetry Cr20 ,2' + 6F s2+ + 14H" ^ 2Cr3+ + 7HzO + 6F s3+ 2.2.3 NUTRIENTS Nitrate Nitrate was determined by the brucine-suphanilie acid spectrophotometric method The nitrate in the wastewaters reacts with brucine in H2SOi at 100 °C to form a yellowish - orange coloured substance, the absorbance of which was measured at a wavelength o f 410 nm. 10 mL o f wastewater was pipeted into hard-glass test tubes. To each of these tubes was added 2 mL of 30% NaCl solution. Tubes were swirled and placed in 1-10° C water-bath and 10 mL o f 7.5 M H2S0 4 was pipetted into each tube and swirled. All the tubes were allowed to stand to come to thermal equilibrium with the environment. Finally, 0.5 mL of the brucine reagent was added to each tube. An extra lube that had the wastewater sample and all other reagents except brucine was added for colour control. The tabes were all swirled again and placcd in a boiling water bath for cxactly 25 min at 95 °C. The tubes were then transferred 38 University of Ghana http://ugspace.ug.edu.gh to a cold water bath and allowed to cool to between 20 °C and 25 °C. The outside o f the tubes was dried and the absorbance o f their contents read against the reagent blank at 410 nm. A set of standard solutions was prepared containing 0.1 - 2.0 mg of NO3-N using analytical grade KN0 3 per liter which, was also treated in the same way as the wastewaters. Calibration curves were plotted of concentration in mg/L against absorbance and the gradient calculated as shown on Fig. 40. The value o f the gradient was multiplied with the individual absorbance o f each sample to calculate their nitrate concentration or the concentrations were just read off the graph. 32 Phosphate The phospho-molybdate method35 was used in the determination of orthophosphate. 100 mL of wastewater and 100 mL of a 0.50 mg/L standard phosphate solution were measured into separate conical flasks. To the contents of each conical flask was added 4.0 mL o f ammonium molybdate solution. After tliorough mixing, 0.5 mL of staimous cliloiide solution was added and mixed to produce a blue colour. Absorbance was read at 690 nm within 5 to 10 min, after the spectrophotometer had been calibrated using the standard phosphate solution. A calibration curve was plotted using 0.1 mg 0.5 mg/mL of PO4-P. 2.2.4 MAJOR IONS Sodium and Potassium The samples were first filtered through a 45 pm millipore filter membrane and the Na and K determinations done photometrically using a Gallenkamp Digital Flame Analyzer. Sodium and potassium were measured at 589 nm and 768 nm respectively, using propane air as fusl-oxidant, after 39 University of Ghana http://ugspace.ug.edu.gh measurements o f the concentrations o f standard solutions o f potassium and sodium nitrates. Calcium Calcium was measured by EDTA (ethylenediaminetetraacetic acid) complexometric titration using a murexide (ammonium purpurate) solid as indicator. 35 The preparation o f the EDTA solution is described in Appendix IV. 100.0 mL of the sample was measured into a conical flask and 2.0 mL o f 1 M NaOH solution added. A pinch of murexide solid was added. The resulting dark red solution was titrated with EDT A solution until a purple color was obtained. This is the end point o f die titration. From the results calcium concentration and calcium hardness of the wastewaters were calculated.3^ M agn e s ium In order to obtain magnesium concentration, total hardness of each wastewater was first determined. The total hardness was determined using EDTA32 which forms complexes with certain ions. 50 mL of the sample was measured into a conical flask, and 1.0 mL of ammonia buffer and a pinch ofEriochrome Black T solid was added. The resulting wine coloured solution was titrated with standard F.DTA solution until an end point o f sea-blue colour was obtained at a pH o f 10. The total hardness was calculated from the results obtained. 3 2 Calcium hardness was subtracted from the total hardness to obtain magnesium hardness and finally magnesium concentration since it is generally believed that the hardness o f water is due to the presence of calcium (Ca) and magnesium (Mg) ions . 32 Sulphate The determination of sulphate was by the turbidimetric method.. 5.0 mL of conditioning reagent was pipeted into 100 mL portions o f samples in 250 mL Erienmeyer. The contents o f the flask were mixed on a magnetic stirrer. While stirring a spooniul o f BaCl2 solid was added and then timed. A white precipitate o f BaSQ4 o f uniform size was formed. Stirring was done at constant speed for exactly i 40 University of Ghana http://ugspace.ug.edu.gh minute and some of the solution was transferred immediately into a cell and the turbidity was measured at 30 sec, intervals for 4 minutes and the maximum reading recorded.. A Philips UV/VIS Spectrophotometer was used to measure the sulphate at a wavelength o f 420 nm. A blank determination using de-ionized without BaCl2 was subtracted from each reading. A standard curve was prepared by using serially diluted samples of 0 - 40 mg/1 S0 4 in 5 mg increments and the concentrations read off. Chloride The determination o f chloride was by Mohr’s method. 100 mL each o f the wastewater and o f de­ ionized water were measured into separate conical flasks and 1.0 mL o f potassium chromate added to each. The resulting solutions were titrated against standard aqueous silver nitrate solution until the first permanent reddish-brown color was obtained at the end point. The de-ionized water was used as a blank to determine the amount of chloride in de-ionized water for use in cases where there was dilution. 2.2.5 TRACE METALS As already stated, on collection o f the samples in pre-treated plastic bottles, they were acidified with concentrated nitric acid to a pH o f about 2 and kept refrigerated until analyzed Since the samples were colloidal in nature, wet digestion was done with nitric acid in a digester (Teflon bomb) for 8 hrs at 160° C to make them clear and colouriess for total metal estimation. For dissolved metal estimation, the sample was acidified immediately after sampling with HN0 3 and then filtered using 45 um millipore filter before storage at 4° C. This was done in the laboratory . 154 41 University of Ghana http://ugspace.ug.edu.gh Digestion by Closed System Digester 7.5 mT. o f each sample was measured into Teflon decomposition vessels o f the digester and to each 2.5 mL o f concentrated HNO3 was added. A blank sample consisted of 7.5 mL o f de-ionized water to which 2.5 mL o f concentrated HNOi has been added. Digestion was done at a moderately high temperature o f 160 °C for 8 hours. The digester was allowed to cool overnight and the digested samples carefully poured out into pre-treated, well- stoppered plastic bottles. The trace metal contents were measured using a Philips PV 9200 flame atomic absorption spectrophotometer.(AAS) Calibration curves were plotted using serially diluted standard solutions o f the different metals being determined. These were read in the AAS and the absorption plotted against the concentrations. The characteristics of the machine employed in the measurements o f the various metals are shown below: Meted Wavelengths(nm) Detection Limit Sensitivity(ppm) Flams Type Copper 324.7 0.001 0.035 OA Cobalt 240.7 0.006 0.048 OA Iron 248.3 0.003 0.06 OA Manganese 279.5 0.001 0.027 OA Aluminium 309.3 0.04 0.39 OA Lead 217.0 0.05 0 . 1 0 OA Zinc 213.9 0 . 0 1 0 . 0 1 OA Chromium 367.9 0 . 0 1 0.05 OA Nickel 232.0 _ 0.59 OA OA = Oxygen - Acetylene. The sensitivities are in mg/L.(ppm) The detection limit o f the AAS for all the trace metals are shown on the Table above. 42 University of Ghana http://ugspace.ug.edu.gh 2.3 LABORATORY TREATMENT OF WASTEWATERS After measurement of the various pollution indicators in the wastewaters, an attempt was made to reduce the levels o f the pollutants in selected wastewaters and to explore the possibility o f recycling the treated water. Wastewaters from the following industries were used: Pioneer Food Cannery Co, Ltd., Ghana Textiles Manufacturing Co. and Tema Lube Oil Co. Ltd. representing the food, textile and petroleum-based industries respectively. 2.3.1 MATERIALS AND PREPARATION OF MATERIALS 2.3.1.1 Soil Samples Soil samples from Bokazo in Western Region, Ekon, Elmina and Ankaful all in Central Region and Asokwa in the Ashanti Region in Ghana used in the studies, were collected from the Institute o f Industrial Research of the Council for Scientific and Industrial Research. Another soil was directly collected from Somanya area in the Eastern Region. This was air-dried and passed through a 600 um sieve to remove sand and graveL Deionized water was next added to it and stirred to form a suspension. The suspended soil was decanted off into a plastic bucket and allowed to stand for ten days for the soil to settle. The settled soil was collected, dried, ground with a porcelain mortar and again sieved with a 600 pm plastic sieve. 65 The former soil samples from the DR, which had already been treated as above and the Somanya sample were thermally activated by heating in a furnace at a temperature of 1000 °C for one hour. The characteristics of the six inactivated soils were determined at the Soil Research Institute o f tire CSIR. 43 University of Ghana http://ugspace.ug.edu.gh 2.3.1.2 Sea-sand Sea-sand was collected from a secluded part of the beach at Old Dansoman in Accra and thoroughly washed with tap and deionized water to get iid o f the salt. It was acid washed with concentrated hydrochloric acid by soaking overnight to remove carbonates. It was then soaked in deionized water overnight, drained, air-dried and finally oven dried at 110 °C overnight. 2.3.1.3 Coconut Husks and Palm Kernel Husks Charcoals Coconut husks were obtained from the Tema Lorry Station in Accra and chopped into very small pieces. Palm kernel husks were obtained from palm fruits bought at Agbogbloshie Market also in- Accra. These were boiled and the fleshy part removed by pounding in a wooden mortar to obtain the nuts. These nuts were dried for a week and cracked open using a stone and the hard husks collected. Both samples were washed well using tap water and sun-dried. The samples were then charred by igniting at 1000°C for one hour in a furnace. The charred residues o f coconut and palm kernel husks were separately boiled in de-ionized water at 110°C for an hour, to leach out ions formed during the chanting. There was further soaking in de-ionized water to dissolve soluble gases like C 0 2 that might have been H apped in them . 6 6 2.3.2 TREATMENT OF WASTEWATERS The raw effluents were analyzed for pollution indicating parameters as already described. The parameters measured were BOD, COD, P 0 4-P, N 0 3-N, turbidity, colour, suspended solids and dissolved metals. Measured volumes of the effluents were subjected to various methods of treatment 44 University of Ghana http://ugspace.ug.edu.gh or cleaning as outlined in details below. The treated samples were then analyzed for the same parameters as was done for the raw. One industiy was sampled and treated at a time and the treatment completed within one week. This period of time was used because for those factors that changed significantly, the change was very evident after only a few days whilst for those that did not change significantly, there was no need for a further wait. 2.3.2.1 Aerobic Treatment One liter of the wastewater was put into an open plastic bottle, which was kept on a laboratory bench at room temperature and shaken at regular intervals for seven days. The pH, redos potential and temperature were monitored daily. After the seven days, the contents o f the bottles were decanted for further analysis. 2.3.2.2 Anaerobic Treatment In the case o f anaerobic treatment, the one-liter plastic bottles were filled to the brim with the wastewater and stoppered well to create anaerobic conditions. 6 The pH, redox potential and temperature were measured daily for seven days. On the eighth day, the samples were decanted and the decanted liquid analyzed. 2.3.2.3 Sand Filtration An improvised plastic column was prepared by cutting off the top of a 1.5 liter mineral water bottle. Holes of about 1.5 mm radii were then made in the bottom by using 6 -ineh nails that had been heated 45 University of Ghana http://ugspace.ug.edu.gh in a charcoal flame. A filter bed of sand about 50 cm in depth was made by packing the treated sea-sand in the plastic mineral water bottle. The top of the plastic bottle was then put at its bottom to direct the filtered water into a receptacle. 100 mL of raw wastewater was passed through a sand filter and the filtrate was collected into another plastic container. \ EjfsCb empty iisinsrsl TOtsr bottle Cut top / / xr.-.u„ „*■at bottom Bottle with top cut off and holes punched at the bottom V / w under the tmttcm oft) Fig. 1 P rspsrstiOii of Bottle for Ss?icl 2.3.2.4 Paper Filtration Watman Qualitative 1 Ca. No. 1001 150 filter paper and a filter funnel were used for the filtration and the filtrate was collected into a well-washed plastic container rejecting the first 100 mL 46 University of Ghana http://ugspace.ug.edu.gh The filtrate was then analyzed. 232 .5 Chemical Coagulation and Sedimentation The treatments were conducted in a wide mouth polythene bottle into which one liter o f the wastewater was poured and one gram of the alum, aluminium ammonium sulphate added. The contents o f the bottle were well shaken and left in the open for seven days whilst the pH, redox potential and temperature were measured on a daily basis. After the seventh day, the contents o f the bottle were decanted and further analysis for pollutants done immediately. 2.3.2.6 Activated Charcoal Treatment 10.0 g of activated charcoal was added to one liter o f wastewater in a plastic bottle and the pH, redox potential and temperature monitored daily for seven days after which the contents were decanted and analyzed. 23 ,2,1 Palm Kernel Husks and Coconut Husks Charcoals Treatments 1 0 . 0 g each of the husks charcoals was added separately to one liter portions of wastewater in plastic bottles and kept for seven days during which period the pH, redox potential and temperature were determined on daily basis after which the contents were decanted and further analyzed. 2.3.2.8 Soft Treatment This treatment was limited to the wastewater of Tema Lube Oil Company because o f logistic reasons. 47 University of Ghana http://ugspace.ug.edu.gh 50.0 g o f each soil was added to one liter portions of the wastewater in plastic bottles and kept for four days after which the contents of the bottles were decanted and filtered through 45 pm millipore filter membrane. The resulting liquid analyzed for trace metals using AAS after further filtration with 45 |.im millipore filter membrane. 48 University of Ghana http://ugspace.ug.edu.gh CHAPTER THREE RESULTS AND DISCUSSION 3.1 RAW EFFLUENTS The results for the determinations o f the levels o f the various pollution indicating parameters are presented in Tables 2 to 4, The EPA limits for wastewaters and the WHO limits for drinkiti£ water are presented in Table 5. 49 University of Ghana http://ugspace.ug.edu.gh TABLE 2 PHYSICAL AMD CHEM ICAL PARAMETERS - Mean Values for Temperature, pH, Conductivity, DO, BOD, COD, TSS & TDS Sample Temp. °C pH Cond. pS/cm DO Mg/L BOD mg/L COD mg/L TDS mg/L TSS mg/L t o r a 28.0 7.70 54420 5.40 3.80 279 - 85.0 t o r b 31.3 7.64 54940 4.70 1 1 . 1 159 56616 84.0 TOR0* 31.2 7.42 53630 3.60 1 2 . 8 - 61595 89.0 TORc 31.5 4.54 12610 3.40 2 1 0 489 - TORct 31.1 6.29 47860 3.50 62.3 489 - 89.0 SWR 26.0 7.63 53100 4.60 3.60 159 53789 82.0 TCM 33.3 5.61 2560 0.90 4740 84461 31.9 20180 CPC 32.9 5.37 290 2.67 937 1806 1765 420 TLC 29.5 7.00 630 0.26 669 1192 421 292 PFC 34.2 6.60 1710 0 . 2 1 375 421 1492 442 BPC 33.4 7.60 150 2.95 76.0 1500 135 3221 GTMC 37.5 10.4 5.14 2.80 80.0 637 1588 60.0 GTP 47.0 13.2 3.23 3.60 547 517 2497 262 Cond. - conductivity Temp. - Temperature TORc*= Wastewater before shut-down of refinery (used in the discussion) TORc = Wastewater after shut-down TORc t= Mean values o f TOR0* and TORc 50 University of Ghana http://ugspace.ug.edu.gh TABLE 3 NUTRIENTS AND MAJOR IONS - MEAN VALUES (mg/L) Sample P 0 4-P NOj-N SO* Cl K Na Ca Mg t o r a 0.14 0.13 2258 19936 480 5563 4503 1396 t o r b 0.23 0 . 1 2 778 20380 480 5433 500 1365 TOR0* 0.27 - 525 19240 515 5520 401 2303 TORc 0.18 - 905 5770 0 . 0 3440 167 681 TOR0'1' 0 . 2 2 - 3150 15628 423 4827 2 1 1 962 SWR 0 . 1 2 0.03 3150 19030 530 5760 399 1392 TCM 8 . 2 2 0 . 1 0 74.8 26.0 195 445 19.2 72.6 CPC 0.93 0.30 42.9 14.3 25.7 16.1 23.7 66.3 TLC 8 . 0 1 0 . 0 1 45.4 168 30.0 108 2 1 . 1 42.1 PFC 4.21 0.13 32.0 154 1 0 . 0 55.4 1 1 . 2 26.5 BPC 8.63 - 30.0 9.5 - - 29.7 9.44 GTMC 8.65 0.08 31.9 1 1 0 35.0 990 22.4 - GTP 2.87 0 . 0 0 1 71.4 14.3 25.0 460 15.8 0.35 51 University of Ghana http://ugspace.ug.edu.gh TABLE 4 MEAN CONCENTRATION OF TRACE METALS (mg/L) Sample NI Pb Fe Mn Zn Cu Co Cr Al tora 0.30 0.26 0.31 0.53 0.54 0.13 0.30 0 . 6 8 0 . 2 0 TOR® 0.26 0.25 0.58 0.46 0.50 0.14 0.30 0 . 6 8 0.64 TOR0* 0.45 0.27 0.35 0.51 0 . 8 6 - - - - TOR0 0.63 0.30 6.63 - 1.50 - - - - TOP„ct 0.37 0.27 3.83 0.60 0.82 0.09 0.28 0.67 0.33 SWR 0.40 0.26 0.33 0.46 0.80 0 . 1 2 - - - TCM 0.23 0.24 3.20 0.53 1.80 0.28 0.35 0.50 2.19 CPC 0.26 0.26 1 . 0 2 0.46 0.53 0.06 0.34 0.46 0.84 TLC 0.40 0.44 2.50 0.53 1 . 2 0 1 . 2 0 - - - PFC 0.27 0 . 2 0 0.58 0.40 1.46 - - - - BPC 0.30 0.25 1.37 0.47 3.64 0.67 - - - GTMC 0.30 0.23 1.17 0.43 0.80 1 . 0 0 GTP - 1.50 0.25 0.70 0.73 - - - 52 University of Ghana http://ugspace.ug.edu.gh TABLE 5 MEAN AND RANGE VALUES FOR ALL INDUSTRIES COMPARED WITH WHO AND EPA LIMITS Parameter Range Mean WHO (1984) EPA (1997) Temp.(°C) 28.0 - 47.0 34.7 <3 °C above ambient PH 5.37 - 13.2 7.90 6.5 - 8.5 6.0 - 9.0 Conductivity (joS/cm) 0.15 - 54940 8550 700 750 Dissolved oxygen 0.21 - 5.40 2.30 80% saturation - Total suspended solids (mg/L) 60 .0-20180 3120 - 50.0 Total dissolved solids (m§L) 31.9 - 56616 800068 1 0 0 0 500.0 Biochemical oxygen demand (mg/L) 3.8 - 4740 929 <3 .0 50.0 Chcmical oxygen demand (mg/L) 159-84461 11317 250 Sulphate (mg/L) 30 .0-3150 2 2 2 2 0 0 1 0 53 University of Ghana http://ugspace.ug.edu.gh TABLE 5 MEAN AND RANGE VALUES FOR ALL INDUSTRIES COMPARED WITH WHO AND EPA LIMITS (continued) Param eter Range Mean WHO (1984) EPA (1997) Phosphate (mg/L) 0 .14 -8 .70 5.04 <0.3 2.0 (Total P) Nitrate (mg/L) 0 .00 -0 .13 0 . 1 0 1 0 . 0 0 . 1 Calcium (mg/L) 11.2-450 77.3 2 0 0 Magnesium (mg/L) 0.35 - 1397 229 150 Total hardness (mg/L) 41.0 -6882 995 500 Chloride (mg/L) 9.5 - 19936 2554 250 600 initial Nickel (mg/L) 0.23 - 0.63 0.34 0.5 Lead (mg/L) 0.20 - 0.44 0.26 0.05 0 . 1 Manganese (mg/L) 0.40 - 0.64 0.47 0 . 1 Zinc (mg/L) 0.53 - 3.64 5.0 2 . 0 Cobalt (mg/L) 0 .28 -0 .35 0.33 Total chromium 0.46 - 0.68 0.54 0.5 (mg/L) Aluminium (mg/L) 0 .20 -2 .19 0 . 2 Sodium (mg/L) 16.1 - 5563 1082 2 0 0 Potassium (mg/L) 10.0 - 480 113 30 Total iron (mg/L) 0 .31 -3 .20 1.72 0.3 2 . 0 Copper (mg/L) 0.06 - 1 . 2 0.41 1 . 0 1 . 0 54 University of Ghana http://ugspace.ug.edu.gh TABLE 6 D IFFERENCES TN THE LEVELS OF POLLUTANTS TN THE WASTEWATER OF TOR AND THE SEAWATER RESERVOIR Parameter TORA Reservoir Difference Temperature °C 28.0 26.0 2 . 0 pH 7.70 ✓ 7.63 0.07 Conductivity(jiS/cm) 54420 53100 1320 DO 5.40 4.60 0.80 BOD ( mg/L) 3.8 3.60 0 . 2 0 COD ( mg/L) 279 159 1 2 0 TSS ( mg/L) 85.0 82.0 3.0 P 0 4 (mg/L) 0.14 0 . 1 2 0 . 0 2 NO3 (mg/L) 0.13 0.03 0 . 1 0 S0 4 (mg/L) 2258 3150 -892 Cl (mg/L) 19936 19030 906 K (mg/L) 480 530 -50 Na (mg/L) 5563 5760 197 Ca (mg/L) 450 399 51 Mg (mg/L) 1397 1392 5.0 Ni (mg/L) 0.45 0.40 0.05 Pb (mg/L) 0.27 0.26 0 . 0 1 Fe (mg/L) 0.35 0.33 0 .0 2 - Mn (mg/L) 0.51 0.46 0.05 Zn (mg/L) 0 . 8 6 0.80 0.06 55 University of Ghana http://ugspace.ug.edu.gh TABLE 6 D IFFERENCES UN THE LEVELS OF POLLUTANTS IN THE WASTEWATER AND SEAWATER RESERVOIR AT TOR ____________________________ (continued from last page)____________ Parameter TORc Reservoir Difference Temperature °C 31.2 26.0 5.2 pH 7.42 7.63 -0 . 2 1 Conductivity t 53630 53100 530 DO 3.60 4.60 - 1 . 0 BOD (mg/L) 1 2 . 8 3.60 9.20 TDS (mg/L) 61595 53789 8806 TSS (mg/L) 89.0 82.0 7.0 P 0 4 (mg/L) 0.27 0 . 1 2 0.15 SO4 (mg/L) 525 3150 -2625 Cl' (mg/L) 19240 19030 2 1 0 K (mg/L) 515 530 -15.0 Na (mg/L) 5520./ 5760 -240 Ca (mg/L) 401 399 -2 . 0 Mg (mg/L) 2303 1392 1 0 1 1 Nx (mg/L) 0.63 0.40 0.23 Pb (mg/L) 0.30 0.26 0.04 Fe (mg/L) 6.63 0.33 6.30 Zn (mg/L) 1.50 0.80 0.70 56 University of Ghana http://ugspace.ug.edu.gh 3.1.1 PHYSICAL PARAMETERS - TEMPERATURE, pH, CONDUCTIVITY DISSOLVED OXYGEN AND TOTAL SUSPENDED SOLIDS The mean temperatures ranged from 28'0°C in the wastewater from Tema Oil Refinery (TOR) to 47.0°C in that from Ghana Textiles Printing (GTP) as shown in Table 2 and Fig. 2. In all but two o f the industries sampled, the temperatures were around the EPA allowed value of less than 3°C above ambient temperature of 33.0 °C for Tema. The offending industries which had values exceeding the EPA values are Ghana Textiles Printing Co. and Ghana Textiles Manufacturing Co. Ltd., which had average temperatures of 37.5 UC and 47.0 °C respectively. The mean temperature for all the industries was 34.7 UC which is close to the mean ambient temperature. Heated water discharged directly into a water course would significantly increase the temperature o f the water, lhis would affect the aquatic ecosystem by increasing metabolism o f the organisms since, biochemical activity often doubles for every 10 “C . 1"1 This could also reduce the ability of the water to hold dissolved oxygen which is important for the survival o f all fauna and flora. 6 -17 Generally, y solubility of gases in water depends on (he lemporalure of the water. As ihc temperature increases, the solubility decreases, thus an increase in the temperature of any receiving water would result in the reduction of dissolved oxygen. 6 Although, an increase in temperature of a few degrees may not be significant, some aquatic ecosystems are very sensitive to minor changes in temperature.1" The spawning behaviour of many fish is triggered by temperature changes. The discharge of heated water into an estuary can also alter the type of plant food available there. The animal inhabitants o f rivers are controlled also by plants that provide them with shelter as well as food. Thus, animals with specific food habits may 57 University of Ghana http://ugspace.ug.edu.gh be ptlitninatiM because, the wanti water could support different kinds of flora, which can alter or interfere with the food web. Also, at temperatures above 40 °C, some flora and fauna can be killed. 67 Moreover, the temperature can have a direct effect on toxicity of pollutants in that a rise of 10 °C in temperature usually, halves the survival time o f a given organism to a particular poison of a specified concentration. 00 The high temperatures o f the wastewaters from the textile industries are due to the scouring process which includes the boiling of the fabric at about 80 °C with a 2 : 1 mixture o f sodium hydroxide and sodium trioxocarbonale (TV) to remove starch remains, wax-like materials, fatty substances like pectin and oils. 11 Another source of heat production is the steaming process in which, the fabric is steamed at temperatures up to 200 °C to ensure the fixation of dye. The pH of an aquatic environment can be changed by added acid or alkali from industrial wastewaters. To maintain a good fish population, it is necessary that the pH of the water is kept in the range 6.7 to 8 .6 .oy,7U The industries, in order o f increasing pH are: Cocoa Processing Co. Ltd., Tuyee Chemical Manufacturing Co., Pioneer Food Cannery, Tema Lube Oil, Tema Oil Refinery, Bridaltrust Paints Co. Ltd., Ghana Textiles Manufacturing Co. and Ghana Textiles Printing Co. as is also shown in fable 2 and Fig. 3. The pH o f four of the eight industries, Tema Lube Oil Co., Tema Oil Refinery (exit for API), PFC and Bridaltrust Paints Co. fell within the allowable EPA and the WHO ranges o f 6.0 to 9.0 and 6.5 to 8.5 respectively. The two textile industries sampled, had Hie highest average pH values of 10.4 and 13.2 respectively which arc vciy basic and well above the EPA upper limit o f 9.0. Mmtah-Boatcng'M reported a pH of 10.9 for Ghana Textile Printing and 10.7 for Akosombo Textiles Limited (ATL), another textile University of Ghana http://ugspace.ug.edu.gh industry that was not worked on, which shows that the wastewaters from textiles industries are generally basic. This is due to the use of sodium hydroxide during the mercerization process where about 32% sodium hydroxide solution is used to give cloth a glossy and smooth appearance and also in the scouring process as has been outlined in the above paragraph. 11 Tuyee Manufacturing Co. and Pioneer Food Cannery had values below the EPA lower limit value o f 6.0. Their wastes are therefore slightly acidic in nature. Ihis may be due to the presence o f organic and inorganic acids produced during the oxidation and fermentation o f food substances as in maize and tuna fish in Tuyee Manufacturing Co.(TMC) and Pioneer Food Cannery(PFC) wastewaters respectively. Amuzu71 in 1995 reported a pH o f 7.2 for Tema Lube Oil Co. Ltd., which agrees with the 7.0 obtained in this study. The average for all the pH values in all the wastewaters of all the industries sampled was 7.92 which fell within both the EPA allowed values o f between 6.0 - 9.0 for wastewater and WHO allowed values for drinking water of between 6.5 - 8.5. / The pH values of less than 5.0 or greater than 9.0 are known to be harmful to most animal. 0 ’11 ,22 Craig72 in 1975 reported that an aquatic medium with high pH of more than 10 or low pH o f less than 2.0 cannot support fish at all. Even within the normal range, the pH has considerable influence on some poisons. For example, whilst NH3 is more poisonous in alkaline than in acid water, cyanide (CN‘) is more poisonous in acidic than in alkaline water.' The conductivity values were generally high except for the values for wastewaters fiom Cocoa Processing Co., TLO and Bridaltrust Paints Co. Ltd. which were below both the EPA value of 750I jaS/cm for wastewater and WHO value of 700 (iS/cm for drinking water as shown in Tabic 2 and 59 University of Ghana http://ugspace.ug.edu.gh Fig. 4. The worst offender was Tema Oil Refinery whose wastewaters had values around 53,000 joS/cm that far exceeded the accepted value of 750 jiS/cm. The conductivity of the reservoir of seawater was 53100 joS, which was similar to that of the Refinery itself. It would be suitable if the wastewaters are discharged directly into the sea, but unfortunately, the wastewaters are poured into drains that empty into the Chemu Lagoon resulting in increases in conductivity o f the Lagoon waters. The other industries which wastewaters are highly polluting with respect to conductivity are Tuyee, Pioneer Food Canneiy, Ghana Textiles Manufacturing Co. and Ghana Textiles Printing. lhe wastewaters o f Cocoa Processing Co., Tema Lube Oil and Bridaltrust Paints, with conductivities of 290 |i£/cm, 630 pS/cm and 150 |iS/cm respective^ were below the EPA allowed value o f 750 uS/cm and thus are to be considered non-polluting. For Tema Lube Oil Amuzu71 in 1995 reported a conductivity value of 362 uS/cm. The value of 3280 uS/cm for GTP reported by Mmtah-Boateng44 agreed quite well with that of 3230 |iS/cm obtained in this study. When the mean conductivity value for all industries o f 8550 p.S/cm is compared to the EPA limit of 750 I^S/cm, there is cause for alarm because it is more than ten times the EPA limit Wastewaters from Pioneer Food Cannery, Tema Lube Oil and Tuyee Manufacturing Co. had very low dissolved oxygen concentrations. The respective values were 0.21, 0.26 and 0.9 mg/L. The mean dissolved oxygen value for all the industries which was 2.30 was appreciable compared to the values for these industries. The dissolved oxygen content for Tema Oil Refinery was generally high, an indication that it contains appreciable quantities of oxygen in spite of the presence o f the large amount of organic matter indicated by the quite high value for 6 o d as shown in Table 2 and 60 University of Ghana http://ugspace.ug.edu.gh Fig. 5. The high values obtained in this study for Tema Oil Refinery, a petroleum-based industry was due to the fast flow o f the wastewater at the point o f sampling resulting in its aeration. This is supported by the fact that the value was higher than that for the seawater reservoir that was relatively stationary. Very low DO values were obtained for the wastewaters from Tuyee, Tema Lube Oil and Pioneer Food Cannery which also had correspondingly high BOD values, an / indication that they contained high concentrations o f organic matter. This organic matter in the water sample is broken down through aerobic processes by bacteria and other micro-organisms in the wastewaters using dissolved oxygen in title wastewaters with the production of water and carbon dioxide, hence reducing Iheir oxygen contents greatly. Compared to Tema Oil Refinery, Tema Lube Oil had a very low DO of 0.26. This could be due to fact that the wastewaters from the latter include some from their kitchen and bathhouses so they must be well inoculated with the right microbes that facilitated the breakdown o f the organic matter, hi the case of Tuyee, the main raw material used was maize which is not only very rich in starches, but also in the other nutrients like phosphates and nitrates that are needed in the growth of micro-organisms in the wastewaters hence increasing greatly the breakdown of the organic matter. Pioneer Food Cannery, like Tuyee, is also an agro-based industry that produces a lot o f easily oxidizable organic matter from using tuna fish as a raw material, so its low DO value is not unexpected, since the breakdown o f the organic matter reduces the oxygen content, resulting in a low DO. Many substances become more toxic as oxygen content o f the water falls. 6 Some fishes live only in wcll-acratcd water, hcncc there is a causc for conecm. Whilst the values obtained in this study for GTP and GTMC were 3.6 and 2.8 respectively, those reported by Mintah-Boateng44 were 4.9 University of Ghana http://ugspace.ug.edu.gh and 0.7 mg/L. The mean value o f suspended solids for all the industries was 3120 mg/L, which far exceeded and is more than 50 times the EPA allowed value of 50.0 mg/L. The most polluting industrial wastewater in this regard is that o f an agro-based industry, Tuyee Manufacturing Co., which contains a lot o f suspended matter in the order o f twenty thousands o f milligrams per liter. With a very high BOD, this pointed to a high concentration of organic materials. This means that, when these wastewaters are discharged, they will increase the solid contents of the recipient water bodies which in lum will have an cfiect on the amount of light that enters the water for aquatic plants to absorb and use for photosynthesis. The amount of plankton for example, could be reduced and this will also rcducc the number of fish. Also, the settled solid particlcs can smother the breeding and feeding sites of fish, which reduces the number o f fish and hence affect the food web, as in the case of heated water. 3 ,5 ,6 ,1 8 The turbidity o f the water which is closely related to the concentration of suspended solids also affects the feeding of fishes since most o f them hunt by sight,7J The other effects of inert solids is that they tend to settle out of the water on to the stream beds and so tend to eliminate algae and plants, consequently altering the fauna.0''" 3.1.2 CHEMICAL PARAMETERS BIOCHEMICAL OXYGEN DEMAND (BOD) The BOD measures the amount of oxygen (mg) that is consumed by a liter o f a water sample in a given time, which for BOD5 is 5 days. 14 The reactions involved in this determination are biochemical in nature. Micro-organisms present in the water oxidize organic materials in the water using oxygen that is dissolved in the water (dissolved oxygen), thus reducing the oxygen content 62 University of Ghana http://ugspace.ug.edu.gh of the water. A high. BOD value is an indication that the oxygen content o f the water is low and vice versa. Apart from Tema Oil Refinery, all the other industries had BOD values that exceeded Ihe EPA allowed value o f 50 mg/L as shown in Table 2 and Fig. 6 . Wastewaters from all (he industries had a mean BOD value o f 929 mg/L, which was about twenty times the EPA allowed value. The most polluting ones were the agro-based industries, Tuyee, Cocoa Processing Co. and Pioneer Food Cannery followed by the textiles industries and then the paint industry. For Tema Lube Oil, Amuzu71 in 1995 reported a BOD value o f 11.0 m gL while the value obtained in this study was 3.80 mg/L. Ghana Textiles Manufacturing Co. and Ghana Textiles Printing with reported values by Mintah-Boateng44 of 525 and 150 mg/L- respectively differ greatly from the values o f 80.0 and 547 mg/L obtained in this study. The variations between the results o f this study indicate that the nature of industrial effluents varies over time. It may also be an indication of increases or decreases in the efficiency o f in-house treatments. For Tuyee, Tema Lube Oil and Pioneer Food Cannery, the high BOD values obtained correlate wilh Iheir low dissolved oxygen (DO) contents. For Cocoa Processing Co., in spite of a high DO value, the BOD value was 937 mg/L which was also high. This could be due to the fact that the right mierobcs for respiration of the organic material were absent or probably, due to the mode of discharge of the wastewater which results in aeration. CHEMICAL OXYGEN DEMAND (COD) Whilst BOD helps in the estimation of the amount of easily oxidizable organic material in a sample of water, chemical oxygen demand (COD) determines tire amount of both organic and inorganic materials that are chemically oxidizable. Unlike BOD, COD involves purely chemical oxidation 63 University of Ghana http://ugspace.ug.edu.gh o f the oxidizable materials using chemical substances like dichromate and permanganate. 6 ,14 As fa r as COD is concerned, almost all the industries had high values. The only exception was again Tema Oil Refinery with a COD o f 279 mg/L, which was quite close to the EPA limit of 250 mg/L. The most polluting industry with respect to COD was Tuyee with a value of 84461 mg/L as presented in Table 2 and Fig. 7. This value far exceeded the 250 mg/L upper limit acceptable to 4 EPA. Next in polluting potential was Bridaltrust Company with a high COD value o f 1500 mg/L, with Tema Lube Oil, Cocoa Processing Co., also producing considerable amount of COD pollution. The high COD value in spite of the comparably low BOD value suggested that the wastewater conlained a lot of inorganic oxidizable materials. For Tema Lube Oil, Amuzu71 reported a COD of 96.0 mg/L in 1995 but the value obtained here was 1192 mg/L. The wastewaters from Tema Oil Refinery had the least mean COD, which was far below the acceptable limit The mean value for all the industries o f 11317 mg/L was more than twenty times the EPA allowed value, which is quite threatening. 3.1.3 TOTAL DISSOLVED SOLIDS (TDS) AND TOTAL SUSPENDED SOLIDS (TSS) In this instance, the extent o f total dissolved solids pollution in increasing order was, Tema Oil Refinery, Ghana Textiles Printing Co., Cocoa Processing Co., Ghana Textiles Manufacturing Co.. Pioneer Food Cannery, Tema Lube Oil Co., Bridaltrust Paints Co. and Tuyee Manufacturing Co. Here, all the industries are potential pollution sources of suspended solids as seen in Table 2 and Fig. 9. Compared with the EPA limit of 50.0 mg/L, the industry that had the lowest value was Ghana Textiles Manufacturing Co. with a level of 60 mg/L, a difference o f 10 units on the higher side from the EP A value. The TDS and the TSS values of 422 mg/L and 292 mg/L o f this study 64 University of Ghana http://ugspace.ug.edu.gh when compared to 252 and 62.0 mg/L obtained by Amuzu71 in 1995 for Tema Lube Oil Co., showed a high increase which is quite alarming. However, as has been already pointed out, this could be a result of the breakdown of their American Petroleum Institute (API) plant. The value o f GTP of 262 mg/L for TSS is rather high compared with what was obtained by Mintah- Boateng44 which was 60.0 mg/L. 4 The EPA allowed value for total dissolved solids (TDS) is 500 mg/L. Judging from the values in Table 2 and Fig. 8 , the offending industries are therefore in order of decreasing gravity o f polluting potential, Tema Oil Refinery, Ghana Textiles Printing, Cocoa Processing Co., Ghana Textiles Manufacturing Co., and Pioneer Food Canneiy. The effluents of Tuyee, Tema Lube Oil and Bridaltrust Paints wastewaters had dissolved solid levels that fell below the EPA limit as shown in Table 2 and Fig. 8 . The solids in Tema Oil Refinery' may be mostly sodium and potassium salts as shown by the large values o f potassium and sodium concentrations. The}' could also contain some magnesium and calcium salts, because the levels o f these parameters were also quite high. The TDS values for both Ghana Textiles/Manufacturing Co. and Ghana Textiles Printing are significantly high due to the large amount o f dye stuffs that they contain which particles were able to pass through the 45 fim filter used in the determination o f the parameter. The quite high value recorded for Pioneer Food Canneiy Co. is from blood and other nutrient materials in the main raw material that is tuna fish that were dissolved in the wastewater. Tuyee had the lowest level of dissolved solids which could be nutrients like nitrates, phosphates, peptides, amino acids etc. present in maize, the main ingredient. The mean value of suspended solids for all the industries was 3120 mg/L which, far exceeded and 65 University of Ghana http://ugspace.ug.edu.gh is more than SO times the EPA allowed value o f 50.0 mg/L. The most polluting industrial wastewater in this regard is that o f an agro-based industry, Tuyee Manufacturing Co., which contains a lot o f suspended matter in the order o f twenty thousands o f milligrams per liter. With a very high BOD, this pointed to a high concentration of organic materials. This means that, when these wastewaters are discharged, they will increase the solid contents of the recipient water bodies which in tom will have an effect on the amount of light that penetrates the water thus maldng it difficult for aquatic animals to obtain enough light for photosynthesis. 3.1.4 NUTRIENTS - NITRATE AND ORTHOPHOSPHATE In Table 3 and Figs. 10, 11 & 12 are presented the levels o f the above mentioned parameters, lhe levels o f orthophosphate ranged from 0.14 mg/L in the effluent o f TOR to 8.65 mg/L in that of GTMC. With the exception o f TOR, all the other industries had concentrations o f orthophosphate that exceeded lhe WHO limit of <0.3 mg/L. The EPA limit for total phosphorus is 2.0 mg/L. This is made up of the three foims in which phosphorus can exist in effluents that is organically bonded phosphorus, polyphosphates and orthophosphates. 13 For most of the industries, the concentration o f orthophosphate alone exceeded the EPA limit for total phosphate. This is an indication that all the industries with the exception o f Tema Oil Refinery were highly polluting in orthophosphate. On the contrary, the phosphate concentration in the wastewater from Tema Lube Oil, another petroleum-based industry was one of the highest, which could be due to th e additives used to blend the base oil. The values for Tuyee and Pioneer Food Cannery are not unexpected, since both o f them are agro-based industries and maize and fish, the main raw materials for the industries are rich in phosphates. It has been mentioned elsewhere in this text that, the wastewaters from their kitchen and bath-houses also discharge into the same drains. These can contain detergents, which 66 University of Ghana http://ugspace.ug.edu.gh are veiy rich in organic polyphosphates, which upon hydrolysis increase the inorganic phosphate content of the wastewaters. Nitrate concentrations were moderate and the mean value o f 0.10 msfL was exactly equal to that allowed by EPA. This is an indication that the concentrations in the wastewaters o f the industries / collectively were not threatening as far as this parameter is concerned. The individual values for some of the industries were below the EPA limit o f 0.1 mg/L, but the wastewaters from Tema Oil Refinery, Cocoa Processing Co. and Pioneer Food Cannery were higher. Also, the concentrations for Tuyee and Ghana Textiles Printing, (hough a little lower than the EPA limit, were dose enough to merit attention. The above parameters, orthophosphate and nitrate are nutrients with high levels in wastewaters can result in greater biological productivity and may eventually upset the ccosystem o f the receiving waters. 13 3.1.5 MAJOR IONS ./ CHLORIDE The EPA limit, for chloride in wastewaters is of 600 mg/L- but for WHO, the limit for drinking water is 250 mg/L. According to the results in Table 3 and Fig. 13, the chloride concentrations in all the industrial wastewaters with the exception o f TOR were below the EPA and WHO allowed values. Ihe values ranged from 9.5 mg/L in the effluent from Bridaltrust Paints to 19936 mg/L in that o f Tema Oil Refinety with a mean of 2554 mg/L. POTASSIUM As shown in Table 3 and Fig. 14 & 15, potassium concentrations in wastewaters from Ghana Textiles Printing, Pioneer Food Cannery, Cocoa Processing Co. and Tema Lube Oil were below 67 University of Ghana http://ugspace.ug.edu.gh or were equal to the WHO limit of 30 mg/L. Unfortunately, the EPA does not have any limit for potassium presently, so the WHO limit for drinking water was used for the discussion. The concentration o f potassium for Ghana Textiles Manufacturing Co. of 35.0 mg/L, was also close to the WHO limit The value for Tuyee was very high, about seven times the allowed value. Also, for Tema Oil Refinery, the concentration was about sixteen times higher but lower than the value 4 tor the unused sea-water. The mean concentration tor all the industries of 113 mg/L tar exceeded the WHO limit which makes industries a potential source of potassium pollution. Potassium is incorporated into cell material, so it can encourage the growth o f micro-organisms. SODIUM The EPA does not have any limits for the concentration of sodium. The mean concentration for all Ihe industries of 1082 mg/L is about five times the WHO allowed value o f 200 mg/L for drinking water. Individually too, except for Pioneer Food Canneiy, Tema Lube Oil and Cocoa Processing Company, all the others exceeded the WHO limit. The Tema Oil Refinery value far exceeded the allowed value which was not surprising because the wastewater is obtained fiom the sea-water used for the cooling process. The sea-water already contains high concentrations of sodium and potassium salts in addition to calcium and magnesium salts. The values for the two textiles industries, Ghana Textiles Manufacturing Co. and Ghana Textiles Printing were also higher than the WHO limit but much lower than the value for Tema Oil Refineiy. The presence of moderately high sodium content in the wastewaters fiom Ghana Textiles Manufacturing Co. and Ghana Textiles Printing is due to the use of large amounts of sodium salts like chlorate and hypochlorite as oxidants and hydroxide in mercerization. 11 A similarly quite high value for Tuyee can be attributed to the use of sodium hydroxide in the steeping o f the milled maize to extract the starch that is used in the production of industrial starch. 75 University of Ghana http://ugspace.ug.edu.gh CALCIUM The mean concentrations o f calcium for all industries of 77.3 mg/L was far below the WHO limit o f200 mg/L. Individually however, the concentration for Tema Oil Refinery was the only one that exceeded this value as presented in Table 3 and Figs. 16, 17 & 18. MAGNESTTJM 4 Also, as f ir as magnesium is concerned, Tema Oil Refinery was the only industry that exceeded the WHO limit o f 150 mg/L. With a mean value for magnesium of 229 mg/L, the WHO limit has been exceeded. As already indicated above, wastes from TOR are disharged through lhe seawater used for cooling. SULPHATE With a mean o f 222 mg/L, the sulphate levels ranged from 30.0 to 3150 mg/L. None o f these values were below the EPA allowed value o f 10.0 mgL. Again, the Tema Oil Refinery levels were the highest, in the magnitude of thousands of milligrams per litre. This was expected, because sea­ water is used for the cooling during the refining o f petroleum and this already contains a lot of sulphates. / 3.1.6 TRACE METALS Compared to the EPA and WHO limits, the levels of the metals were found to be generally high and hence, the industrial wastewaters are quite polluting in trace metals as indicated in Table 4 and Fig. 19 - 27. 3.1.6.1 Nickel (Ni) With a EPA allowed value of 0.5 mg/L, the mean concentration of Ni in the industrial wastewaters 69 University of Ghana http://ugspace.ug.edu.gh was 0.30 mg/L. The individual levels ranged from 0.23 - 0.37 mg/L. The values did not exceed the allowed value but were high enough for the industries to be potential sources of this trace metal pollution. The least polluting industry was Tuyee, an agro-based industry. Generally, the most polluting group o f industries was the petroleum-based, followed by the agro-based and the chemical and textiles industries. In a study in Nigeria in 1991, Osibanjo76 reported a level o f < 0.010 mg/L in the wastewaters o f textiles industries in Nigeria, lhus, the value o f 0.30 mg/L obtained for Ghana Textiles Manufacturing Co. was higher but still below the EPA limit. 3.1.6.2 Lead (Pb) Lead is highly poisonous to man and other living organisms. However, it has been reported by Van Loon5 to be probably essential in low quantities. The concentrations o f Pb were generally high with a mean value o f 0.26 mg/L for all the industries. The values for the various industries ranged from 0.20 mg/L to 0.44 mg/L as compared to the WHO and EPA limits o f 0.05 and 0.1 mg/L respectively. All the industries are therefore potential sources of Pb pollution, the most polluting and the least polluting being Tema Lube Oil, a petroleum based industry and Pioneer Food Cannery, an agro-based industry respectively. Just as for nickel, the most polluting industrial group is Ihe petroleum-based industries, then the chemical and textiles and finally the agro-based industries. Biney59 and Osibanjo76 reported lead concentrations of 0.65 mg^L and < 0.10 mg/L in the wastewaters of textiles industries in Ghana and Nigeria respectively. Osibanjo76 also reported 0.20 m gl for the oil industry whilst the values quoted for Tema Oil Refinery and Tema Lube Oil were 0.27 and 0.44 mg/L respectively. Thai of Tema Oil Refinery was in agreement unlike the concentration for Tema Lube Oil. 70 University of Ghana http://ugspace.ug.edu.gh 3.1.6.3 Iron (Fe) With a mean value of 1.72 mg/L and a range of 0.31 to 3.83 mg/L, the values of Fe for all the industries exceeded Ihe WHO allowed value of 0.3 mg/L. The most polluting wastewater was TOR0 which was the wastewater from the API of Tema Oil Refinery with a level o f 3.83 mg/L, followed by Tuyee with a value o f 3.20 mg/L and then Tema Lube Oil with a level of 2.5 mg/L. 4 Tema Oil Refinery and Tema Lube Oil are petroleum-based and therefore, it can be concluded that the petroleum-based industries are the most potentially polluting o f all the industries sampled. The least polluting industry was Pioneer Food Cannery, an agro-based industry with a level of 0.58 mg/L although CPC and TMC, the other agro-based industries had quite highvahies. Biney39 and Osibanjo70 reported 0.31 mg/L and 0.50 mg/L in textiles effluents in Ghana and Nigeria respectively. Osibanjo76 also reported 1.45 mg/L for the oil refinery. The allowed value for Fe by EPA is 2.0 mg/L. The industries that exceeded this value were TOR, Tuyee and Tema Lube y 3.1.6.4 Manganese (Mn) / The concentration of manganese in all the wastewaters exceeded the WHO maximum limit of 0.1 mg/L. The range was 0.25 to 0.60 mg/L and the mean o f 0.46 mg/L was about five times the allowed value. The most polluting wastewater was TORc from the .API o f Tema Oil Refinery with a value o f 0.60 mg/L, followed by TOP/ 1 o f Tema Lube Oil with a value of 0.53 mg/L. Tema Oil Refinery and Tema Lube oil are petroleum based so it can be deduced that the petroleum based industries are the most polluting in Mn. The least polluting industry was Pioneer Food Cannery and Cocoa Processing Co., which are agro-based. TMC, another agro-based industry had values that were comparable to those o f the petroleum-based industnes. This may be due to 71 University of Ghana http://ugspace.ug.edu.gh contamination from the wearing away o f the metal from the grinding milk vised for grinding the com which the caustic soda solution used for the extraction o f the starch could have dissolved. Whilst the levels for the textiles industries were 0.43 and 0.25 mg/L for GTMC and GTP respectively, Osibanjo76 reported 0.83 mg/L for the textiles industries in Nigeria. 4 3.1.6.5 Zinc (Zn) The various values ranged from 0.70 to 3.64 mg/L with a mean of 1.28 mg/L. The EPA limit for zinc of 2.0 mg/L was exceeded by only the wastewater from Bridaltrust Paints Co. Ltd. with a concentration o f 3.64 mg/L. Concentrations in the various industrial wastewaters, however fell below the WHO limit of 5.0 mg/L. The paint industry had the highest zinc concentration followed by Pioneer Food Cannery, an agro- based industry. In spite o f the fact that they all fell below the EPA limit for the wastewater from Bridaltrust Paints, some of the industries had levels that demand attention. These were Tuyee, Pioneer Food Cannery and Tema Lube Oil Co. with values of 1.80, 1.46 and 1.20 respectively mg/L. Binoy59 and Osibanjo76 reported values of 0.50 mg/L and 0.05 mg/L for (he textiles industries in Ghana and Nigeria respectively whilst for the petroleum (oil) industry, Osibanjo76 reported 0.25 mg/L. The values of 0.80 and 0.70 mg/L reported for GTMC and GTP are quite comparable to that o f Biney. 59 3.1.6.6 Copper (Cu) The values ranged from 0.06 to 1.2 mg/L, with a mean level of 0.41 mg/L. Individually, the WHO and EPA limits of 1.0 mg/L was equalled only by the wastewater from GTMC. The lowest 72 University of Ghana http://ugspace.ug.edu.gh concentrations of Cu were obtained in the wastewaters from Tema Oil R.efinery and Cocoa Processing Co. Biney59 and Osibanjo70 reported values o f 2.75 mg/L and 0.12 mg/L for the textiles industries in Ghana and Nigeria respectively. The values obtained in this study were not however in agreement with these values for ihe petroleum-based industries, the values were in agreement with the value of 0.14 mg/L reported by Osibanjo. 76 3.1.6.7 Cobalt (Co) The values ranged from 0.28 lo 0.35 mg/L and the mean was 0.33 mg/L. The industries that had the highest concentrations o f cobalt were Tuyee and Cocoa Processing Co. with values of 0.35 and 0.34 mg/L rcspcctivcly. The least values in this case were recorded for Tema Oil Refinery, a petroleum industry. Unfortunately, the levels for the other industries could not be determined because the AAS developed problems. Osibanjo76 reported less than 0.10 mg/L for the textiles industries in Nigeria, and this could be art"indication o f generally low levels o f Co in industrial wastewater. No literature values were obtained for Ghana. The WHO and EPA values too were not available for comparison. 3.1.6.8 Chromium (Cr) The range was 0.46 to 0.68 mg/L with a mean of 0.54 mg/L. The WHO and EPA limits of 0.5 mg/L for total chromium was exceeded by Tema Oil Refinery and Tuyee which are petroleum and agro-based industries respectively. Cocoa Processing Co., an agro-based industry had a value of 0.46 mg/L which was just slightly lower than the WHO and EPA limits. The mean value o f 0.54 73 University of Ghana http://ugspace.ug.edu.gh mg/L for all the industries was just a little higher than the allowed value of 0.5 mg/L for both EPA and WHO. Chromium ions (Cr*6) are common contaminant of drinking water while Cr+3 is not so common. 3.1.6.9 Aluininiuin (Al) / Individually, all the values exceeded the WHO allowed value o f 0.2 mg/L. Ihe industry with the highest level o f Al was Tuyee. This is not very surprising; strong caustic soda solution used to extract starch from the milled com may dissolve aluminium, an amphoteric metal that may be present in lhc metallic parts o f the com mills as well as the vats used for steeping o f maize. The levels o f Al for the individual industries ranged from 0.01 to 2.19 mg/L. The mean o f 1.15 mg/L was about six times the WHO value. 3.2 LABORATORY TREATED WASTEWATERS Table 7 shows the % decomposition o f tj.le soils and Table 8 , the texture, phosphorus and potassium contents of the soils. The levels of pollutants in the untreated and treated wastewaters are shown in Tables 9 to 16 while EPA and WHO allowed limits for waste waters and drinking water respectively are shown in Table 5. Variations in turbidity (which has a direct relationship with suspended solids), BOD, P 0 4-P and N 0 3-N for the different types of treatments for each industry are shown in Fig 28 to 39 for comparison, ihe values quoted for the treated wastewaters are for the last day. 74 University of Ghana http://ugspace.ug.edu.gh TABLE 7 THERMAL ACTIVATION OF SOILS - WEIGHINGS Source o f soil Wt. O f soil (g) Wt. O f residue (g) Wt. O f decomposed portion (g) % decomposition Ankaful 50.0006 43.4630 6.54 13.1 Bokazo 50.0000 47.0527 2.95 5.90 Elmina 50.0003 43.5564 6.44 12.9 Somanya 50.0002 44.6990 5.30 1 0 . 6 Ekon 50.0006 42.9358 7.06 14.1 Asokwa 50.0329 44.7207 5.31 1 0 . 6 TABLE 8 PHYSICAL CHARACTERISTICS, POTASSIUM AND PHOSPHORUS CONTENTS OF THE SOILS Soil Location % Sand % Silt Clay Texture P K Somanya 5.81 6.97 87.0 Clay 2.90 19.4 Bokazo 14.9 67.0 18.2 Silt/Loam 10.9 4.61 Asokwa 8 . 1 0 9.29 82.6 Clay 1.34 9.44 Ankaful 9.53 58.2 32.3 Silt/Clay/Loam 2,08 12,7 Ekon 1 1 . 1 15.6 73.2 Clay 8.62 85.0 Elmina 10.9 8.64 80.4 Clay 1.49 1156 The units of potassium and phosphorus are mg/g 75 University of Ghana http://ugspace.ug.edu.gh TABLE 9 SOME PHYSICAL, CHEMICAL PARAMETERS AND NUTRIENT LEVELS BEFORE AND AFTER TREATMENTS - TEMA LUBE OIL CO. LTD Treatment PH Cond. jiS/cm Turb. ' (NTU) Colour (TCU) BOD (mg/L) p o 4-p (mg/L) NOj-N mg/L None 6.72 411 108 250 2 2 0 8.72 0.0055 Aerobic 7.24 411 8.30 25.0 2 1 . 0 7.83 0 . 0 0 2 2 Anaerobic 6.56 424 34.1 45.0 2 0 . 0 6.80 0.0029 Sand filtration 7.82 164 2.40 5.00 13.0 0.37 0.0014 Paper filtration 7.62 335 2 2 . 8 75.0 16.0 1.55 0.0045 Alum 4.94 702 2.90 1 0 . 0 10.5 0 . 1 1 0.0031 Act charcoal 7.26 592 7.40 2 0 . 0 1 2 . 0 3.50 0.0036 PKC 7.28 336 27:0 75.0 13.0 3.07 0.0028 NTU = Nephelometric Turbidity Units PKC = Palm kernel husks charcoal Cond. - conductivity Turb. = Turbidity 76 University of Ghana http://ugspace.ug.edu.gh TABLE 10 SOME PHYSICAL, CHEMICAL PARAMETERS AND NUTRIENT LEVELS BEFORE AND AFTER TREATMENTS - PIONEER FOOD CANNERY CO. Treatment PH Cond. liS/cm Turbid (NTU) Colour (TCU) BOD mg/L PO„-P mg/L NO3-N mg/L None 6.52 1465 75.0 500 170 2 1 . 2 0.61 Aerobic 8 . 0 2 1055 31.0 ' 125 105 16.7 0.61 Anaerobic 6.41 1380 34.0 1 0 0 1 1 0 16.5 0.59 Sand filtration 6.89 6 6 . 8 4.50 2.50 7.75 0.65 0.59 Paper filtration 6.72 1320 72.0 485 160 2 2 . 0 0.60 Alum 5.34 1204 73.0 - 135 1 2 . 1 0.58 Act charcoal 7.52 998 33.0 - 16.5 12.3 0.60 PKC 7.59 562 4 7 .O / 18.0 11.9 0.59 PKC = Palm kernel husks charcoal 77 University of Ghana http://ugspace.ug.edu.gh TABLE 11 SOME PHY SIC AL,CHEMIC AL PARAMETERS AND NUTRIENT LEVELS BEFORE AND AFTER TREATMENTS - GHANA TEXTILES MANUFACTURING CO. Treatment PH Cond. (j.S/cm Turb. (NTU) Colour (TCU) BOD (mg/L) P 0 4-P (mg/L) (mg/L) None 11.7 1722 48.6 6000 190 4.06 0.71 Aerobic 9.60 1175 29.0 6000 150 3.72 0.81 Anaerobic 1 1 . 6 1150 44.0 6000 1 1 0 3.66 0.76 Sand filtration 8 . 1 0 153 1.30 40.0 2 . 0 0 0.46 1 . 0 0 Paper filtration 11.4 1695 46.5 6000 175 0.40 0.70 Alum 8 . 6 8 1403 18.0 3580 25.0 0 . 8 8 0.62 Act charcoal 9.62 1274 17.4 - 25.0 3.42 0.69 PKC 9.80 1098 23v4 / - 145 3.39 0.63 Ekon clay 1 0 . 1 1287 9.70 - - 3.30 0.74 Elmina clay 9.72 1186 19.5 - - 3.22 0 . 8 6 78 University of Ghana http://ugspace.ug.edu.gh TABLE 12 MEAN CONCENTRATIONS OF TRACE METALS BEFORE AND AFTER TREATMENTS - TEMA LUBE OIL CO. (mg/L) Treatment Fe Pb Ni Co Cu Zn None 0.19 0.03 0.07 bdl 0.011 0.17 Aerobic bdl bdl 0.065 bdl 0.011 0.09 Anaerobic bdl bdl bdl bdl 0.001 0.11 Sand filtration bdl 0.11 bdl bdl 0.004 0.11 Paper filtration bdl bdl 0.026 bdl 0.001 0.08 Alum 1.31 bdl 0.13 bdl 0.001 0.18 Act charcoal bdl bdl 0.062 bdl bdl 0.08 PKC bdl bdl bdl bdl bdl 0.09 bdl = below detection level 79 University of Ghana http://ugspace.ug.edu.gh TABLE 13 AVERAGE LEVELS OF TRACE METALS BEFORE AND AFTER TREATMENT 'WITH SOILS (mg/L) - TEMA LUBE OIL CO. Soil Fe Pb Ni Cm Z ji None(Raw wastewater) 0.19 0.03 0.07 0 . 0 1 1 0.17 Ankafui bdl bdl bdl bdl 0.19 Asokwa bdl bdl bdl bdl 0.15 Bokazo bdl bdl bdl bdl 0.23 Ekon bdl bdl bdl bdl 0.19 Elmina bdl bdl bdl bdl 0.18 Somanya bdl bdl bdtl bdl 0.35 80 University of Ghana http://ugspace.ug.edu.gh TABLE 14 PERCENTAGE CHANGES IN VALUES OF WASTEWATER PAR4METERS AFTER TREATMENTS - TEMA LUBE OIL Treatm ent pH Conductivity Turbidity Colour BODs PO*-P NO 3-N Aerobic 7.74 0 92.3 90 90.5 1 0 . 2 60.0 Anaerobic 2.38 3.18 68.5 82 90.9 2 2 . 0 47.3 Sand filtration 16.4 60.1 97.8 98 94.1. 95.8 74.6 Paper filtration 13.4 18.5 78.9 70 92.7 82.3 18.2 Alum 26.5 70.8* 97.3 96 95.2 98.7 43.6 Activated charcoal 8.04 44.0 93.2 92 94.6' 59.9 34.6 Palm kernel husks 8.33 18.3 75.1 70 94.1 64,9 49.1 * = increase 81 University of Ghana http://ugspace.ug.edu.gh TABLE IS PERCENTAGE CHANGES OF WASTEWATER PARAMETERS AFTER TREATMENTS - PIONEER FOOD CANNERY CO. LTD. Treatment pH Conductivity Turbidity Colour BODs P 04-P NO3-N Aerobic 23.0* 28.0 58.7 75.0 38.2 21.5 - Anaerobic 1.69 5.80* 54.7 80.0 35.3 22.3 4.08 Sand filtration 5.64 95.4 69.8 99.5 95.4 97.0 3.92 Paper filtration 3.07 9.9 3.00 2.90 5.88 7.31 2.45 Alum 18.1* 17.8 75.4 - 92.1 43.0 4.89 Act. charcoal 15.3* 31.9 56.0 - 90.3 42.1 2.77 PKC 16.4* 61.6 37.3 - 89.4 43.8 3.59 PKC = Palm kernel husks chiircoal * = increase 82 University of Ghana http://ugspace.ug.edu.gh TABLE 16 PERCENTAGE CHANGE IN VALUES OF WASTEWATER PARAMETERS AFTER TREATMENTS - GHANA TEXTILES MANUFACTURING CO. Treatment PH Conductivity Turbidity Colour BOD; P 0 4-P NO3-N Aerobic 17.8 31.8 40.3 0 2 1 . 1 8.37 18.7 Anaerobic 0.51 33.2 9.47 0 42.1 8.73 23.3 Sand filtration 30.7 91.1 97.3 99.3 99.0 8 8 . 6 10.9 Paper filtration 2.48 1.57 4.32 0 7.89 1 0 . 0 - Alum 25.7 18.4 63.0 40.3 8 6 . 8 78.3 37.3 Activated charcoal 17.6 74.0 64.2 - 8 6 . 8 15.8 29.7 83 University of Ghana http://ugspace.ug.edu.gh The discussions will be mainly on the effect the various treatment methods had on BOD, nitrogen and phosphorus salts, suspended solids and trace metals in this work since present day treatment o f effluents focuses on the reduction of these parameters . 13 Results are shown in Tables 7 to 16 and Figs. 28 - 39. 3.2.1 AEROBIC TREATMENT 'Alien the three wastewaters were aerated, the BOD values for Tema Lube Oil was reduced from 220 ms/L to 21.0 mg/L, a decrease o f 90.5 %, For Pioneer Food Cannery Co., the decrease was from 170 mg/L to 105 mg/L, which amounted to a percentage decrease of 38.2. In the case o f Ghana Textiles Manufacturing Co., the decrease was 21.1 % from 190 mg/L. to 150 mg/L. These results show that BOD reduction by aeration for the three industries was highest for the wastewater from Tema Lube Oil. lhe Tema Lube Oil wastewater sampled contained domestic wastewater from their kitchen as well as their bathrooms, so it is more iikciy io be dosed with more of the micro-organisms ihal are nccessary for lhe breakdown of the organic materials in the wastewaters. A close look at Tables 9 - 1 6 shows that there is generally a direct relationship between the turbidity and BOD values, the BOD increases as turbidity increases and vice versa. University of Ghana http://ugspace.ug.edu.gh Fig. 28 - % Change o f BOD with Treatment for TLC 1 0 0 -r- T r e a t m e n t Fig. 29 - % Change o f BOD with Treatment for PFC 85 University of Ghana http://ugspace.ug.edu.gh Fig. 30 - % Chiingc of BOD with Treatment for GTMC Fig. 31 - % Change of Turbidity with treatment, for TLO 86 University of Ghana http://ugspace.ug.edu.gh 80 T T re a tm e n t Fig. 32 - % Change of Turbidity with treatment for PFC Treatment Fig. 33 - % Change o f Turbidity with Treatment for GTMC 87 University of Ghana http://ugspace.ug.edu.gh The turbidity is also closely related to the suspended solids; the higher the suspended solids, the higher the turbidity of a wastewater. From this, it can be deduced that, the amount of suspended solids is highest in Tema Lube Oil since it had the highest turbidity, followed by Pioneer Food Cannery and finally by Ghana Textiles Manufacturing Co. As expected, the BOD of Tema Lube Oil was highest but that for GTMC was higher than for Pioneer Food Cannery. When aerobically treated, the turbidity o f the wastewater from Tema Lube Oil decreased from 108 to 8.30, a decrease o f 92.3 %, that of Pioneer Food Cannery decreased from 75.0 NTU to 31.0 NTU, a percentage of 58.7. For Ghana Textiles Manufacturing Co., the turbidity decreased from 48.G NTU to 29.0 NTU, corresponding to a decrease of 40.3 %. The high SOD of the raw or untreated wastewater from Terns Lube Oil may be due to the fact that, that wastewater contained more settleable and other solids that are organic and were easily oxidized by micro-organisms producing that high BOD value. Generally, during the treatments of all the wastewaters, the turbidity values decreased and hence the resulting BOD values were lower than for the raw wastewaters o f each industry. The effect of aerobic conditions on PO4-P reduction was not significant. The level in the wastewater from Tema Lube Oil dropped by 10.2 %, while the level in the wastewater from Pioneer Food Cannery reduced by a percentage of 21.5 and for the Ghana Textiles Manufacturing Co. wastewater, a decrease o f 8.37 % was observed. The generally low reduction observed for all samples, indicated that aerobic treatment is not a very suitable method for PO^-P reduction. This is because, nutrient salts in the form of nitrogen and phosphorus salts are reduced only to a small extent by aerobic treatment which is a biological method o f wastewater treatment, just like anaerobic treatment13 The biological processes 88 University of Ghana http://ugspace.ug.edu.gh remove barely 2 0 - 30 percent o f total phosphate present in a wastewater and this is used in the growth of algae. The processes involved in this reduction are biochemical, hence die extent of reduction depends on the presence o f the right microbes, and other nutrients that are necessary for the incorporation o f the phosphate by the microbes into cell material, thus removing <* them from the wastewater. The low levels of phosphate reduction may therefore be attributed to either a low concentration of the right micro-organisms that utilise orthophosphate as nutrients or the absence of some other nutrients that are necessary for its incorporation. Tig. 34 - % Change o f P 0 4-P with Treatment fof TLO 89 University of Ghana http://ugspace.ug.edu.gh Treatment Fig. 35 - % Change o f PO4-P with Treatment for PFC Treatment Fig. 36 - % Change o f PO4-P with Treatment for GTMC 90 University of Ghana http://ugspace.ug.edu.gh Nitrate (N 0 3 -N) reduction was highest for Tema Lube Oil and was 60.00 %, from 0.0055 mg/L to 0.0022 mg/L. For Pioneer Food Cannery, there was no change and for Ghana Textiles Manufacturing, there was rather an increase o f 18.7 %, from 0.71 nig/L to 0.81 mg/L. This could have resulted from the microbial breakdown of complex nitrogen- containing compounds into inorganic nitrates, in the wastewater from Ghana Textiles Manufacturing Co. which was measured by our method . 6 Thus, even though aerobic treatment will be a useful method for N 0 3-N reduction in the wastewater from Tema Lube Oil, it will not be uselul for the other two industries. Treatment Fig. 37 - % Change o f NOs-N with Treatment for TLO 91 University of Ghana http://ugspace.ug.edu.gh Fig. 38 - % Change o f NOs-N with Treatment for PFC 40 T 30 Z 6m 2 0z 10 0 a) ® & E =Q. g Treatment Fig. 39 - % Change o f NO 3-N with Treatment for GTMC 92 University of Ghana http://ugspace.ug.edu.gh Thus, even though aerobic treatment will be a useful method for N 0 3-N reduction in the wastewater from Tema Lube Oil, it will not be useful for the other two industries. The usefulness o f the method therefore can be said to be related to the type o f effluent, which composition depends on the raw materials and the methods o f production employed. 3.2,2 ANAEROBIC TREATMENT Keeping the wastewaters under anaerobic conditions caused a reduction in almost all the parameters measured to some extent as shown in Tables 14-21 . BOD reduction was 90.9 % for Tema Lube Oil, 35.3 % for Pioneer Food Cannery, and 42.1 % for Ghana Textiles Manufacturing Co. The Tema Lube Oil wastewater sampled contained domestic wastewater from their kitchen as well as their bathrooms, so it is more likely to be dosed with more o f the micro-organisms that are necessary for the breakdown o f the organic materials in the wastewaters. Also, unlike what obtains in Pioneer Food Cannery where the wastewaters are in open gutters, the sampling at Tema Lube Oil was done underground, where there is a semi- anaerobic environment that favours digestion. Although the treatment brought significant reduction in BOD, the value o f 20.0 mg/L obtained for the treated wastewater from Tema Lube Oil, was below the EPA limit o f 50.0 mg/L for wastewaters. Like the samples from the other two industries, it was above die WHO limit for potable water o f < 3.0 mg/L. Hence, the treated waters cannot be used as potable water. The PO4 -P reduction o f 8.73% for Ghana Textiles Manufacturing was the lowest compared with 22.29% and 22.02% for Pioneer Food and Tema Lube Oil respectively. These values are in agreement with the up to 30 % reduction reported by Kemi13 for biologically treated sewage. 93 University of Ghana http://ugspace.ug.edu.gh A reduction o f 47.3 % in the level o f NO3-N was obtained with anaerobic treatment applied to the wastewater from Tema Lube Oil. In the case o f Pioneer Food Cannery Co., the reduction was only 4.08% and for Ghana Textiles Manufacturing Co., it increased by 18.7%. This increase o f 18.7 % in the treated water from Ghana Textiles Manufacturing Co. was unexpected but could be due to nitrate formation by the microbial breakdown of complex nitrogen-containing compounds. 6 The nitrate concentrations for the raw, untreated samples were below the WHO accepted value o f 10.0 msfL but all the same, the nitrate levels of the treated samples were measured after the treatments, to find out the usefulness o f the method in reducing the nitrate concentration in wastewaters. The percentage turbidity decreases were 68.5, 54.5 and 9.47 for Tema Lube Oil, Pioneer Food and Ghana Textiles respectively, the same order as for the aerobic treatment. This is so because, during the treatments, a large amount of the suspended solids in the Tema Lube Oil wastewater settled easily and by the end o f the seven days, most o f the r e m a in in g amount had also setded, reducing the turbidity drastically. In the case o f Pioneer Food Cannery, the colloidal wastewater which was bloody started coagulating and settling alter about three to four days while for Ghana Textiles Manufacturing Co., after the seven days, the wastewater was still colloidal. 3.2.3 FILTRATION METHODS In Table 7, the clay contents of the soils were established and this was necessary because, the clay component o f soils is highly adsorbent as far as metlalic ions are concerned Table 8 is showing the decomposed fractions of the individual soils used, which is mainly organic. It was necessary to decompose the organic component of the soils, because it can be a source of 94 University of Ghana http://ugspace.ug.edu.gh organic pollution to the wastewaters, during their use to treat the wastewaters. With the filtration methods, the percentage reduction in the parameters measured was in many cases varied. In the case o f sand filtration wliich proved to be the best, apart from the nitrate reduction which was very low for the wastewaters from Pioneer Food Cannery and Ghana Textiles Manufacturing Co., the BOD, PO4 -P, NO3-N and turbidity reduction levels were significantly close and very high as seen in Tables 8 , 9 and 10. Here, again, the turbidity of the raw and treated wastewaters increased with the BOD. In all instances, the new BOD values tell below the EPA allowed value o f 50.0 mg/L but only the treated wastewater from Ghana Textiles Manufacturing had a BOD of 2.0 which was less than that of the WHO allowed maximum value o f 3.0 mg/L. This treated water could therefore be used as potable water if disinfected either by chlorination, ozonation or ultra-violet irradiation. 1 7 The PO4-P reduction followed the order, Pioneer Food > Tema Lube Oil > Ghana Textiles Manufacturing with the respective percentage reductions o f 97.0, 95.8 and 8 8 .6 . The order for turbidity reduction was Tema Lube Oil > Ghana Textiles Manufacturing Co. > Pioneer Food Canneiy with per centage reductions o f 97.8 , 69.8 and 97.3% respectively. Paper filtration was useful in the reduction of BOD and PO4 -P for Tema Lube Oil but not in nitrate reduction as seen in Tables 14 - 16. Again, the BOD decreased with the turbidity as in the other methods already discussed. The method can be useful in the reduction of turbidity in the wastewater from Pioneer Food Cannery and other wastewaters from the food industry that contain a large amount of suspended matter. 95 University of Ghana http://ugspace.ug.edu.gh 3.2.4 CHEMICAL COAGULATION (ALUM ADDITION) This was another very useful treatment method in that. most, of the parameters were very much reduced in the wastewaters. In BOD reduction, the percentage reduction was 95.2 for Tema Lube Oil, 92.1 for Pioneer Food and 8 6 . 8 for Ghana t extiles Manufacturing Co. in general, the amount of suspended matter is greatly reduced by chemical precipitation which foims soUleable floes that are removable for example by simple decantalion, hence they are not available for oxidation to increase the BOD of the mixtures after the treatment, resulting in low BOD values. The turbidity was also reduced very much by the method, which was in consonance with the low BOD values. The values were significantly reduced through a range o f 97.3% in Tema Lube Oil to 63.0 % in Ghana Textiles Manufacturing. lhe direct precipitation method used is very useful in the reduction o f phosphorus too. P 0 4-P levels were reduced veiy much but all the new values still exceeded the WHO value o f less than 0.3 mg/L. Reduction in NO 3-N was generally low. Its values were already below lhe WHO allowed value of 10.0 iiig/L, so it was not very necessary to monitor it, but there was the need to find out how the method affects the nitrate levels in wastewaters for possible use in future. 3.2.5 OTHER METHODS OF TREATMENT Activated charcoal, palm kernel charcoal, Ekon clay and Elmina clay additions also gave interesting and significant results as shown in Tables 1 4 - 2 1 . Like the charcoals, clay particles possess large surface area per unit mass, and have been reported to be highly adsorptive. The suspended solids arc adsorbed on the clay particlcs which settle more rapidly with the suspended solids, thus making the solution clear, with a resulting BOD decrease. 96 University of Ghana http://ugspace.ug.edu.gh The adsorptive properties o f the clays and the activated charcoal as well as the other charcoals were clearly shown by their very effective reduction of the levels of the trace metals also. 3.2.6 TRACE METALS REDUCTION The levels o f lhe dissolved (race metals found in the wastewaters were noi high but the fact that aquatic organisms are able to accumulate them and they can be introduced to man and cause problems made it necessary' to find ways and means of their removal from the wastewaters. Ni. Cu, Pb. Fe. Zn and Co in the untreated wastewater from Tema Lube Oil were 0.070 mg/L. 0.011 mg/L, 0.03 mg/L, 0.19 mg/L, 0.17 mg/L and below detection ievel in the same order as shown in Table 7. When the sample was treated under aerobic conditions for seven days, there was no change in the level o f Cu which was fortunately already below both the EPA and WIIO allowed values o f 1.0 mg/L for wastewater and 1.0 mg/L for drinking water respectively. The levels of other metals decreased in some cases while in some they increased. Fe and Pb were below detection limit after the treatment Before the treatment, Pb with a concentration o f 0.03 in the untreated wastewater was below both the respective EPA and WHO limits of 0.1 and 0.05 mg/L but Fe with a concentration o f 0.19 mg/L in the untreated water was above the WHO value of 0.05 mg/L. After treatment, the Fe concentration was below detection level. Ni decreased from 0.070 to 0.065 mg/L, which is quite insignificant. In lhe anaerobically treated sample, Zn decreased to 0.09 mg/L from 0.17 mg/L whilst Cu, Fe, Ni and Pb fell below detection level. 97 University of Ghana http://ugspace.ug.edu.gh When sand filtered, Cu, Ni and Fe were not detected after the treatment. Zn decreased to 0.11 mg/L from 0.17 mg/L. Pb however, increased significantly from 0.03 mg/L to 0.11 mg/L. This could not be easily be accounted for. On treatment with the chemical coagulant (alum), the concentration of Ni increased to 0.130 mg/L from 0.070 mg/L, an increase of about 50% and Fe also went up to 1.31 mg/L from 0.19 mg/L. This could be due to interferences as a result o f impurities in the alum used. Cu and Pb were however not detected. Three other methods, paper filtration, activated charcoal and palm kernel husks charcoal treatments made significant reductions in the levels of all metals measured. Paper filtration reduced Cu, Fe and Pb to levels below detection limits whilst Zn decreased from 0.17 mg/L to 0.08 mg/L which was below the WHO allowed value for drinking water of 0.10 mg/L. Ni was reduced to 0.026 mg/L. In the case of activated charcoal, apart from Ni and Zn, the remaining metals were reduced to levels below detection limits, Zn decreased from 0.17 mg/L to 0.08 mg/L and Ni concentration was virtually the same, only reducing to 0.062 mg/L from 0.070 mg/L. With the exception o f Zn which was detected to have decreased from 0.17 mg/L to 0.11 mg/L, the levels of the remaining metals measured were below the detection level after the use o f palm kernel husks charcoal for treatment. This showed a good performance of the material in the treatment of these wastewaters. As shown in Table 18, soil treatment seemed to have no effect on Zn but almost all the soils reduced the levels of the other trace metals, such that they were even not detected in the treated waters. This is expected, since the soils act as adsorbent and cation exchanger, adsorbing and exchanging some metals for others on their surfaces. But generally, Pb and Cu 98 University of Ghana http://ugspace.ug.edu.gh tend to be adsorbed most strongly and Zn and Cd are usually held more weakly so they are more labile and hence can remain in the treated wastewater. * 6 This was exactly what was observed as far as Pb and Zinc were concerned, hi an article in ‘The State of the Environment in Nigeria11, some of the water quality parameters measured for partially treated water from the WEMABOD Treatment Plant in Nigeria actually showed higher values than for the untreated wastewater. Here, treatment involved the addition of alum to the incoming wastewater from the factories and subsequent discharge without any sedimentation. 99 University of Ghana http://ugspace.ug.edu.gh CHAPTER FOUR CONCLUSION The levels of all the parameters measured showed that all the wastewaters from the industries were polluting to some extent. It can be concluded that the wastewater o f TOR. is a major source of dissolved salts, having a veiy high conductivity. Tt also contained a large amount of dissolved solids as a result o f the sea-water used in the cooling process which is then discharged into the Chemu Lagoon . 50 Wastewaters from the textiles industries contained large amounts o f total suspended solids (TSS) and total dissolved soiids (TDS) as well as basic materials, as indicated by the nigh pH values. They also had high BOD and COD values in addition to intense colours. The agro-based industries were particularly polluting in biochemical oxygen demand (BOD) and chemical oxygen demand (COD) and had low dissolved oxygen (DO). They also contained appreciable concentrations of nutrients like orthophosphates and nitrates which could encourage the growth o f micro-organisms resulting in a secondary' BOD load. The levels of almost all the measured parameters exceeded the EPA limits or guidelines, a clear indication that the industrial wastewaters are potentially polluting. Generally, it can be concluded that the wastewaters from the petroleum-based industries especially the wastewaters from TOR, were the most polluting in trace metals, followed by the chemical and paint industries and finally by the agro-based industries. Generally, the levels of trace metals were 4.1 INDUSTRIAL WASTEWATER EFFLUENTS AND POLLUTION 100 University of Ghana http://ugspace.ug.edu.gh not high but considering the tact that even in small concentrations they are toxic and also that aquatic organisms are able to bioaccumuiate them, they should be a source of concern. No healthy biological life can exist in a stream with high BOD, pH, poor transparency, no dissolved oxygen and a high temperature. 77 and it is not surprising that water bodies like Chemu and Korle Lagoons have degenerated into the state in which they are today. Even with a dilution factor of 8 , the industrial effluents could contribute significantly to pollution of the rivers, lagoons and the sea. Industrial effluents and domestic wastes disposal will continue to pose problems to mankind as long as increased industrial activity and human aggregation around the industrial areas are concerned. Wastewater disposal does not only affect rivers, lakes and other water bodies, but it also has an effect on land, which we depend on for our food. 4.2 RECOVERY OF USEFUL WATER FROM INDUSTRIAL WASTEWATER EFFLUENTS Of the six methods investigated in the treatment of wastewaters from Tema Lube Oil Co., Pioneer Food Cannery Co. Ltd. and Ghana Textiles Manufacturing Co., sand filtration stood out as the single best method of treatment. It proved to be the singular, mo3 t effective treatment method which, was quite useful in reducing the pollution parameters from all the three industries, even to levels below the maximum limits. It was found out to be particularly useful in the case o f PFC, where the experiment showed that, the method can be employed effectively and cheaply in treating not only their wastewaters, but those from other agro-based industries to produce water of sufficiently good quality for re-use for other acivities like crop and animal fanning or for disposal into the environment. Chemical coagulation, done by alum addition, also showed some 101 University of Ghana http://ugspace.ug.edu.gh potentiality, but the addition of alum increased the pH and conductivity o f the wastewaters, so the method has to be used with a lot o f caution, with the end use of the refined water in mind. Apart for paper filtration, which was found to be the least effective method, the resi of the methods tried were found to be useful in die reduction o f individual parameters in specific wastewaters. Sand filtration, having been identified and singled out as a comparatively cheap and effective method of wastewater treatment, however have some limitations to its use, because o f the waste sand that will be produced. It is therefore the wish of the workers that more work will be done to estimate the amount of waste sand that will be generated annually in the event o f the large-scale employment of this method in wastewater treatment to find out probable and appropriate uses. 4.3 RECOMMENDATIONS Existing factories should be encouraged to acquire suitable treatment plants whilst new ones should be sited so that effluent disposal is possible without nuisance and damage to the potable water bodies. Towards inis end, the establishment of industrial estates should be promoted so that the industries collectively can put together infrastructure for treatment of wastes including wastewaters to make it cheaper. Also, some of the pollution problems will need to be tackled at their source, that is pollution problems should be considered at the early stages of planning human settlements and industrial activities. Pollution from industrial and other human activities must be brought under control before some success can be achieved in reclamation or restoration of many rivers and other water bodies. With concerted effort, this can be achieved. Raw materials and the methods of production could also be chosen in such a way that, the volume of wastes including wastewaters is not only reduced but the toxicity is also reduced. 102 University of Ghana http://ugspace.ug.edu.gh REFERENCES 1. Perry. J.: Vanderklein, E. Water Quality Management of A Natural Resource; Blackwell Science: USA 1996; pp 29 - 31. 2. Ghana Environmental Action Plan: 1991; Environmental Protection Council; Accra, Ghana, Vol. 1, p. 40. 3. Allowav, B. J. Heavy Metals in Soils: Blackie and Sons: Glasgow, Scotland, 1990. 4. Strategic Options for Redressing Industrial Pollution: 1995; Industry & Energy Division, West Central Africa Dept., Federal Ministry o f Housing & Environment; Lagos, Nigeria; Vol. 1, p. 1138. 5. Van Loon, Jon C. Selected Methods o f Trace Metal Analysis : Biological and Environmental Samples: John Wiley 8l Sons: New York, USA, 1985; pp 3 - 95. 6 . Hynes, H. B. N. The Biology o f Polluted Waters: University of Liverpool: UK, 1971; pp 53 - 63, 69 - 85. 7. Kirkwood. R. C.; Txingley, A. J. Clean Technology &. The Environment: Blackie Academic & Professional: London, UK, 1995; p. 7, 102. 8 . Global Environmental Monitoring System Water Operational Guide, WHO (World Health Organization), Geneva, 1987. 9. Ei-Hinnawi, E.; Hashmi, M The State of the Environment. UNEP, Buttersworth, London, UK, 1987; pp 29-31. 10. Meadows, D. H.; Meadows, D. L.; Randers, J. Beyond the T .writs: Earthscan Publications: London, 1992; pp 54 - 57. 103 University of Ghana http://ugspace.ug.edu.gh 11. The State of the Nigerian Environment: 1995; Industry & Energy Division, West Central Afhca Dept., Federal Ministry o f Housing & Environment, Lagos, Nigeria, 1995; Vol. 1, pp 7 - 14. 12. Curry-Lindahl, K. Conservation for Survival: GoUancz: London, UK, 1972. 13. Kemi, Kemira The Handbook of Water Treatment: Helsingborg, Sweden, 1990; p. 11 — 21, 23, 35. 14. Otiaway, J. H. The Biochemistry of Pollution: Edward Arnold: London, UK, 1980; pp 1 - 9. 15. Defining An Environmental Development Plan for Nigeiia: 199d; Industry & Eneigv Division, West Central .Africa Dept.,Federal Ministry of Housing &. Environment: Lagos, Nigeria, 1995; Vo!s 1 —2. 16. Higgins, T. E. Pollution Prevention Handbook: CRC Lewis: London. 1995; pp 6 - 11. 17. F.nger. E. D.; Smith, B. F. Environmental Science A study o f Interrelationships. 4m ed., Win C. Brown, USA, 1992; pp 347 - 374. 18. Committee for Inland Fisheries of Africa; Working Party on Pollution and Fisheries, Review o f Heavy Metals in the African Environment, Accra, Ghana, 1991; pp 7 - 12. 19. Guidelines for Drinking Water Qualiiy, WHO (World Health Organisation) 2nd ed. Vol.l, Geneva; pp 39, 45 - 57. 20. People’s Daily Graphic, (1998) 10* October, Accra. 21. Bruce-Tagoe, N. P. A. K.; M. Phil. Part 1 Project Work, University of Ghana, Legon, Ghana, July 1996. 22. Jones, J. R. E. Fish and River Pollution; In Water Pollution 2: Causes and Effects, L. Klein (ed.), London, Buttersworth, 1972; pp 254 - 310. 104 University of Ghana http://ugspace.ug.edu.gh 23. Sanderson, R. D.; Jacobs, E. P. Abstracts o f Papers, 6 th International Chemistry Conference in Africa, Ghana; Ghana Chemical Society: Accra, 1995; SL08 24. Benavides, L. Presented at the Expert Group Meeting on Local Management on Hazardous Wastes from Small-scale and Cottage Industries, Lagos, Nigeria, 1992. 25. Defining an Environmental Strategy for the Niger Delta: 1995; Industry & Energy Operation Division, West Central Africa D ept Federal Ministry of Housing & Environment Lagos, Nigeria, 1995; Vol. 1. 26. Alloway, B. J.; Ayres, D. C. Chemical Principles of Environmental Pollution; Blackie Academic & Professional: USA, 1993; pp 147 - 148. 27. Wilson, A, L. The chemical Analysis o f Water: Anal. Sc. Monograph No. 2, 1974; p. 36, 56, 57, 83, 87, 8 8 . 28. Mackereth. F. J. H. Water Analysis for T imnnlnoist Fresh water Biological Association, Scientific Publication, 1963; No. 21, p. 13. 29. Potter, E. C.; White. J. F. J. AppL Chem. 1957, 7, 459. 30. British Standards Institution, BS 2690:1965, The Institution, London, 1965; pp 11 - 19. 31. Hissel, J.; Price, J. Bull. CEBEDEAU. 1959, 44, 76. 32. American Public Health Association (APHA), et al Standard Methods for the Examination of Water and Wastewaters, 16lh ed.; W'ashingion, 1992; pp 37 - 42, 684 - 685 33. Riley, J. P. in Riley, J. P.; Skiirow, G. Eds. Chemical Oceanography; Vol. 2, Academic: 1965, pp 299-301. 34. Official Methods of Analysis o f Association of Official Analytical Chemists International Official Methods of Analysis, 15th Ed. Vol. 1, AO AC Inc., Virginia, USA 1990: p. 21. 105 University of Ghana http://ugspace.ug.edu.gh 35. Kumagai, Y. ; Wakata, T. Kogyo Yosui, 1971, 158, 48. 36. Moore, W. A.; Kroner, R. C.; Ruchhoft, C. C. Anal. Chem. 1949, 21. 953. 37. Jii'ka, A. M.; Carter, M. J. Anal. Chem. 1975, 47, 1397. 38. Baughman, G. L.; Butler, B. T.; Sanders, W. M. Water Sewage Works 1969, 116, 359. 39. Amuzu, A. T. Tne Environmental Consequences o f the Uncontrolled Discharge of Domestic and Industrial Effluents into the Korle Lagoon in Ghana, Birmingham, UK, 1975. 40. Amuzu. A. T. A Survey of the Water Quality' o f the KLorle Lagoon, WRRI, Accra, Ghana, 1976 41. JerJdns, D.; Medsker, L. L. Anal. Chem. 1964, 36, 610. 42. Kemphake, L.; Hannah, S.; Cohen, J. Water Res. 1967, 1, 205. 43. Fishman, M. J.; Skoustad, M. W. Anal r iii-m 1964, 36, 1643. 44. Mintah - Boateng, S.: A Survey o f Industrial Effluents. Accra. Ghana, 1995. 45. Covolos, G.; Panesar, M. R.: Parry. E. P. Anal. Chem. 1976, 48, 1693. 46. Jacobsen, E.; Tandberg, G.; Anal. Chim. Acta., 1973, 64, 280. 47. ZalL D. M.; Fischer, D.; Gamer, M. Q. Anal Chem. 1956, 28, 1665. 43. Moss, M. L.; Mellon, M. G. Ind. Eng. Chem. Anal. Ed. 1942, 14, 862. 49. Smith, G. F.; Richter, F. P. Phenanthroline and substituted Phenanthroline Indicators: Smith Chemical Co.: Columbus, Oliio, 1944. 50. BlaedeL W. J.; Laesig, R. H. Anahvt. Chem. 1966, 38, 186. 51. Kakulu, S. E.; Osibanjo, O.; Ajayi, S. O. Envii'on. hit. 1987, 13, 347. 52. Akoto-Bamford, S. Biol. Trace Elem. Res. 1990, 26: 279. 53. Onwumere, B. G.; Oladeji, A. A. Esotox.Environ.Safety. 1990, 19, 123. 106 University of Ghana http://ugspace.ug.edu.gh 54. Sande113 R. B.; Onishi, H. Photometric Determination of Traces o f Metals; Part 1. 4m ed. Wiley: New York. 1978, 55. Akatsuka, K.; Atsuga, I. Anal. Chem. 1989, 61, 216. 56. Good, S. R.; Matthews, R. J. Anal. Chem. 1978, 50, 1608. 57. Heaarich, J. B.; Ridaington, I. M. Spectrochim. Acta. 19S2, 11, 457. 58. Ambasht, R. S.; Ambasht, P. K. Environment & Pollution (An Ecological Approach'); Students, Friends: Lanka, Varanasi - 221005, India, 1992; 2nd Ed- p. 7, 50, 84, 139. 59. Biney. C. A.: Coastal Management o f Accra - Specialist Papers, Environmental Pollution, Vol. 5, Accra, Ghana. (1991), pp 1 — 39. 60. Amekor, E.; VV atcr Quality Studies of Inputs to tbs Chemu Lagoon, Restoration o f Chemu Lagoon Project, EPA, Accra, Ghana, 1995. 61. Torgfce. I. B.Sc. Final Year Project Report, University of Ghana, Legon, July, 1997. 62. Ghana Standards Board, Accra, Ghana, personal communication, 1999. 63. Pitt. D. Water In A Warmer World: Pacific Press: Karon. Wellington 5, New Zealand, 1995. np 5. 18. 64. Vaikovic, Vlado Trace Metal Analysis: Taylor & Francis: London, 1975. 65. Brenya, E. F., Institute o f Industrial Research,(CSIR), Accra, Ghana, personal communication, 1998. 6 6 . Lartev. R. B., Institute of Industrial Research of CSIR, Accra, Ghana, personal communication. 1997. 67. Butcher, R. W. Journal of Ecology 1933, 21, 58. 6 8 . Herbert, D. W. M.; Downing, lv. M.; Merkens, J. C. Verhandlung Internationale Vereinigung der Limnologie, 1955,12, 789. 107 University of Ghana http://ugspace.ug.edu.gh 69. Huet, M. Presented at the Transactions of 3rd Seminar o f the Public Health Service, US, 1962; pp 60 -162. 70. Ellis. M. M.; Water Quality Standards for Freshwater Fishes, Special Science Report, USFWS, 1944; Vol. 2, pp 1 -15. 71. Amuzu, A. T. (1995) Plant Effluent Quality for Tema Lube Oil Co. Ltd, Accra, Ghana. 72. Craig, C. R.; Baski, W. F. Water Research. 1975, LL. 621. 73. Pentelow, F. T. K. Report of Salmon and Freshwater Fish Association 1949, 3L 4. 74. Jones, J. R. E. Journal o f Animal Ecology'. 1943, 12, 115. 75. Tuyee Manufacturing Company, personal communication, 1997. 76. Osibanjo, O. Hydrogeological and chemical basic data acquisition from NMPC Operational areas. Technical Report to Nigerian National Petroleum Coiporation, Lagos, 1988. 77. Jegede, M. O. M.Sc., University of Ibadan, Nigeria. 1977. 108 University of Ghana http://ugspace.ug.edu.gh A P PEN D IX I Map of Tema showing Industries sampled M IC H E L c a m p A ra a Liable to Flood A S H 1 A M A N BR IDA L TRUS T C OMM . 1 C OMM . 2 A c c r a 109 University of Ghana http://ugspace.ug.edu.gh APPENDIX II CALIBRATION CURVES FOR SOME PARAMETERS Nitrate mg/L Fig. 40: CALIBR ATION CURVE FOR THE DETERMINATION OF NITRATE 1 1 0 University of Ghana http://ugspace.ug.edu.gh Cone, of Fe (mg/L) Fig. 41: CALLIBRATION CURVE FOR IRON (Fe) Cone, of Mn (mg/L) Fig. 42: CALLIBRATION CURVE FOR MANGANESE J 11 University of Ghana http://ugspace.ug.edu.gh Cone, of Fb (mg/L) Fig. 45: CALLIBRATION CURVE FOR LEAD Cone, o f Zn (mg/L) Fig. 46: CALLIBRATION CURVE FOR ZINC 112 University of Ghana http://ugspace.ug.edu.gh Cone, of Cu (mg/L) Fig. 43: CALLIBRATION CURVE FOR COPPER 0.045 0.04 - 0.035 - <„ 0.03 ■o § 0.025 - 1 ° ' 0 2 < 0.015 0.01 0.005 n I I I I 2 4 6 8 10 Cone, of Ni (mg/L) Fig. 44: CALLIBRATION CURVE FOR NICKEL 113 University of Ghana http://ugspace.ug.edu.gh GRAPHICAL PRESENTATION OF THE VARIOUS PARAMETERS IN THE INDUSTRIAL WASTEWATERS APPENDIX III 1 - l l l l I I I II I I I < D Q O Q C M « 0 ^ , t 0 < D r^ * c0 8 8 8 8 industry Fig. 2 14 T 12 - 10 -- I I I4"l I 1 2 - 1 1 1 00 1A 00 1B 00 1C Q C M t n ^ m c D h - c o 8 Industry Fig. 3 60 j 50 - I 4 0 -3 ;j| 30 - 1 2 0 - o 10 - m l lc 00 1A 00 1B 00 1C 00 1D 2 l 3 - * 4 5 6 7 8 Fig. 4 114 University of Ghana http://ugspace.ug.edu.gh Fig. 5 Industry Fig. 6 100000 80000 ^ 60000 - 8 40000 O 20000 < CD O O CM CO 8 8 8 8 Industry Fig. 7 115' University of Ghana http://ugspace.ug.edu.gh University of Ghana http://ugspace.ug.edu.gh Fig. 8 University of Ghana http://ugspace.ug.edu.gh 10 - ■ft 8 I 6 & 4 " o. 2 - 0 I — l ' I < C O O Q c‘* c° ' ,r,0 V %> 3 S tandardization 0.8241g o f NaCl previously dried at 140 °C was dissolved in enough distilled water and diluted to 1 liter in a volumetric flask. 1 mL of this solution is equivalent to 1.0 mg o f Cl ions. Potassium chromate Indicator 5.0g o f potassium chromate (K^CrO.,) was dissolved in 100 mL o f water. Silver nitrate solution was added dropwise to produce a slight red precipitate of" silver diroinate and tlxe solution was filtered. The filtrate is used as the indicator. 127 University of Ghana http://ugspace.ug.edu.gh APPENDIX V SAMPLE CALCULATIONS BIOCHEMICAL OXYGEN DEMAND Pioneer Food Cannery Company Limited BODj = (BODj -BOD j) x Dilution Factor Titre value for BOD] = 7.90 mL Titre value for BQD; = 3.30 mL Dilution Factor = 100 BOD 5 = (7.90 mL - 3.30 mL) x 100 = 4600 mg/L CHEMICAL OXYGEN DEMAND Bridaltrust Paints Company Limited Dilution Factor = 4 Titre value for sample = 10. 00 mL l itre value for blank = 25.40 mL Cone. ofFe(NH 4 )S0 4 = 0.0249 M COD (mg/L) - 800 x (25.40 mL - 10. 00 mL) x 4 x 0.0249 M = 1271.2 mg/L University of Ghana http://ugspace.ug.edu.gh PHOSPHATE DETERMINATION (P 0 4-P) Ghana Textiles Printing Limited Dilution Factor = 10 LTV Spectrophotometer reading - 0.0685 mg/L Phosphate concentration = 0.0685 x 10 mg/L = 0.685 mg/L FORMULAE FOR OTHER DETERMINATIONS Total Hardness (mg CaCOj/L) Average titre x 1000 Sample volume Calcium (Ca2+) mg/L Sample volume Calcium Hardness (mg CaCOj/L) Calcium ions (mg/L) 0.4 Magnesium Hardness (mg C aCO /L ) Total Hardness (mg CaCCyL) - Calcium Hardness (mg CaCCyL) Magnesium (Mg2+) mg/L Magnesium Hardness mg/L x 0.43 University of Ghana http://ugspace.ug.edu.gh