Department of Nuclear Sciences and Applications

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    Assessing the effects of geographical origin and production practices on the levels of heavy metals in honey from three regions in Ghana
    (International Journal of Environmental Studies, 2024) Klutse, C.K.; Adotey, D.K.; Serfor-Armah, Y.; Boateng, R.Y.; Forson, A.
    To evaluate the impact of production methods and geographical origin on honey quality, honey from three regions in Ghana was analysed using INAA and FAAS for the presence of some selected metals. Five metals were found in all the ninety samples as Mg (321.1 mg/kg), Cu (56.2 mg/kg), V (8.18 mg/kg), Fe (3.28 mg/kg), and Pb (0.0400 mg/kg). Co and Cr were detected in 12% and 45% of the samples respectively but As, Cd, and Hg were not detected. The concentrations of Pb varied significantly based on production practices. Cu, Mg, and V showed differences based on geographical sources, according to the Kruskal Wallis test at p < 0.05. Co was below the WHO levels for drinking water and Cr, Cu, Fe, Mg and V were above the WHO levels. Ultimately, the honey source, as opposed to production practices, affected the metal content and potentially, honey consumption can have health risks.
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    Groundwater fluoride contamination in Ghana and the associated human health risks: Any sustainable mitigation measures to curtail the long term hazards?
    (Groundwater for Sustainable Development, 2021) Sunkari, E.D.; Adams, S.J.; Okyere, M.B.; Bhattacharya, P.
    This study reviewed groundwater fluoride and the associated human health risks in Ghana. The physical and chemical properties of fluorine that make it soluble in the soil and aquifer materials were carefully reviewed. The pathways through which fluoride gets into groundwater were also reviewed. Fluoride concentrations in groundwater can be as high as 67 mg/L. Its natural concentration in water depends largely on the nature of the geologic formations; fluoride-bearing minerals, anion exchange capacity of aquifer materials (OH− for F− ), pH, temperature and residence time of waters within a particular formation. High F2 concentrations in groundwater are due to geogenic and anthropogenic sources. The fluorosis-endemic parts of Ghana are only restricted to northern Ghana, where elevated groundwater fluoride concentrations (0.05–13.29 mg/L) in the North East Region, Northern Region, Upper East Region, and surrounding communities have been reported. The elevated groundwater fluoride concentrations are as a result of intense water-rock interaction, ion exchange reactions, and mineral dissolution from the Bongo Granitoids and Voltaian sediments. Children in the fluorosis-endemic parts of Ghana are exposed to the intake of more fluoridated water than the other age groups and thus, children have higher non-carcinogenic risks. Although almost all age groups show evidence of dental fluorosis, children are the hypersensitive population. It is recommended that sustainable defluoridation methods such as adsorption, precipitation, membrane separation and ion exchange techniques be employed to curtail the menace of dental fluorosis.
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    A comparative review of the mineralogical and chemical composition of African major bauxite deposits
    (Heliyon, 2023) Zainudeen, N.M.; Mohammed, L.; Nyamful, A.; Adotey, D.; Osae, S.K.
    Bauxite, which is the main raw material that aluminium is extracted from was discovered in Africa in the early 1900s. Currently, the production and export capacities of the African Bauxite ore are about a third of the World’s total capacity. However, the processes leading to the final finished product of; surface mining of the ore, refining ore into alumina and finally extracting the pure aluminium metal in high energy consuming smelters that employ the Hall-H´eroult electrolysis process; seldom take place inside Africa. The main goal of this work is to analyse the mineralogical and geochemical characteristics of bauxite deposits from some prominent bauxite producing and exporting countries of Africa in order to fashion out if a trend exist for the type of source rocks. Judging from the data obtained, gibbsite is found to be the main aluminium oxide in all the bauxite deposits with slight occurrence of boehmite in 3 out of the 13 deposits, while goethite is the main oxyhydroxide iron mineral. The compiled results of the various investigations highlighted the fact that the deposits are of diverse qualities with respect to world standard of major element content of bauxite; with average percentage concentration in the ranges as: Al2O3 (43.73–61.25), Fe2O3 (1.55–34.25), SiO2 (0.42–10.84); except two of the deposits with alumina content less than 40%. With evaluated silica moduli less than 8 for only two (2) of the deposits (4.76 and 6.94), the rest have higher moduli that ranges between (14.49 and 75.45). The higher percentage of iron oxide content (>20) in six (6) out of the 13 ore deposits, allowed the deposits to be grouped into three (3) categories of grades; high alumina ore, ferruginous ore, siliceous ore and combination of each. Source rock of the deposits were determined through geochemical and petrographic considerations of laterisation products of the rocks through evaluation of the weathering indices of; Chemical Index of Alteration which was in the range (97.16–99.98) while the Ruxton ratio ranged between (0.0133–0.2100); signifying the parent rock underwent intensive weathering process. This is indicative of the source rocks of the Bauxite deposits being either (i) anorthositic, (ii) argillite and dolerite, (iii) granulite and feldspathic gneiss, and/or, (iv) mafic-basaltic andesite igneous. Awareness of new and yet-to-commence emerging bauxite producing African countries was created, by highlighting the economic impact those respective countries will experience when that mining sector is developed for the aluminum in dustry at home and world at large.
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    Characterisation and rare-metal potential of the Winneba-Mankoadze pegmatites, Southern Ghana: Evidence of two pegmatite fields
    (Journal of African Earth Sciences, 2023) Adams, S.T.; Lichtervelde, M.V.; Dampare, S.M.; et al.
    In southern Ghana, the region along the coast between Accra and Cape Coast hosts a large number of pegmatites mineralized in lithium, niobium-tantalum and tin. The pegmatites occur in many distinct groups, each extending over several kilometers. They intrude metasedimentary units of the Birimian Supergroup, and are associated with early to late orogenic granite intrusions which are metaluminous, sterile, and too old to be potential parental granites for the pegmatites. In this study, we characterized the Winneba-Mankoadze group of geographically coeval pegmatites, using field description, petrography, rare-metal mineralogy and accessory mineral geochemistry on micas, garnet and Nb–Ta–Sn minerals, in order to determine its rare-metal potential and to investigate its origin. The results indicate that the pegmatites are part of the albite-spodumene type of the Lithium–Cesium–Tantalum (LCT) family. The rare metal mineral assemblages are particularly complex and display relevant oxide species such as columbite- and wodginite-group minerals, tapiolite, microlite, cassiterite and rutile, which are evidences of an extremely evolved magmatic system. Based on mineral assemblages, whole rock geochemistry, and mineral geochemistry on garnet, micas and the CGM, two pegmatite fields are distin guished in the Winneba-Mankoadze group, and an anatectic origin is proposed. For the first time in West Africa, we fully describe a highly fractionated LCT-family pegmatite field comparable to the most evolved pegmatite bodies in the world.
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    Removal of zinc oxide nanoparticles in aqueous environment using functionalized sorbents derived from sago waste
    (Springer, 2022) Droepenu, E.K.; Wee, B. S.; Chin, S. F.; Kok, K. Y.
    The increase in sago processing industries especially in Malaysia has inadvertently created its waste effect on the environment. The study therefore modified the raw sago waste residue (hampas) generated by three (3) chemical processes; esterification, acetylation and phosphorylation. The as-prepared sorbents were characterized by surface area analyser (BET), Fourier transform infrared (FTIR) spectroscopy, field emission-scanning electron microscopy (FE-SEM) and energy-dispersive X-ray spectroscopy (EDX). Thereafter, their sorption efficiencies were evaluated on zinc oxide nanoparticles in lake water in a laboratory-scaled column-bed sorption study. Spectra analysis confirmed the presence of ester and ether functionality in the esterified and acetylated samples, whereas phosphoric ester and amine functionality were present in the phosphorylated sample. The acetylated sample recorded the largest surface area (29.02 m2/g) and degree of substitution (1.99). The experimental data established that acetylated sago residue recorded the maximum column capacity of 4.50 mg/g in all the parameters examined. Meanwhile, increase in influent concentration (1.51–5.04 mg/L) and flow rate (4.20–6.60 ml/min) decreased the breakthrough time while increase in column-bed height (3–7 cm) increased the breakthrough time for the three sorbents. However, Adams–Bohart model adequately described the behaviour of the sorption process better than Thomas and Yoon–Nelson models. The results suggested that acetylated sago residue is potentially scalable for removing zinc oxide nanoparticles from water.
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    Comparative Study of Two Acid Digestion Protocols for Evaluating Potentially Toxic Elements in Surface Sediments Influenced by Sewage Discharge and Sand Mining Activity
    (Springer, 2022) Asare, E.A.
    The study aimed to compare two acid digestion techniques, the partial digestion (total-recoverable) protocol by USEPA 3051 (HNO3) and total digestion (total-total) method by Hossner (Methods of soil analysis: Part 3. Chemical methods, SSSA and ASA, Madison, pp 49–64, 1996), to recommend an efficient method for evaluating ten potentially toxic elements (PTEs) (i.e., As, Pb, Cu, Cd, Mn, Zn, Cr, Ni, Co, and Fe) concentrations in surface sediments influenced by sewage discharge and sand mining activity. Inductively coupled plasma-optical emission spectroscopy (ICP-OES) analyzed the PTEs after sample treatment and extraction. The hot plate Hossner method exhibited high PTEs extractability than the microwave-assisted USEPA 3051 method. Generally, As, Pb, Cu, Cd, Mn, Zn, and Cr extracted by both methods depicted sediment background concentrations. No significant differences in concentrations between the two digestion techniques for Ni, Co, and Fe were observed in all samples. Furthermore, lower negative biases were observed between the two digestion techniques for extracting Ni, Co, and Fe in all sediment samples. Also, positive correlations between the total-recovery protocol and the total-total method were observed for Ni, Co, and Fe concentrations in all study sites. This implied that both total-recoverable and total-total methods were efficiently extracted Ni, Co, and Fe in all sediment samples. In addition, the total-recoverable method partially extracted other PTEs in the sediment samples, unlike the total-total technique. The total-recoverable (USEPA 3051) method can be recommended for extracting PTEs in sediment samples originating from lithogenic sources on the condition of using a strong acid such as HF or strong acids combination. The study revealed that sediment physicochemical characteristics influence the extraction of PTEs in sediment. Therefore, sediment factors should be considered when selecting incomplete acid digestion methods for extracting PTEs.
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    Trend analysis of anthropogenic activities affecting trace metals deposition in core sediments from the coastal and four rivers estuary of Sarawak, Malaysia https://link.springer.com/article/10.1007/s11356-021-17008-1#auth-Ebenezer_Aquisman-Asare
    (Springer, 2022) Asare, E.A.; Assim, Z.; Wahi, R.; Bakeh, T.; Dapaah, S.S.
    This study reports the concentrations of trace metals in core sediments profile from the coastal and four rivers estuary in the Kuching Division of Sarawak, Malaysia, and the controlling mechanisms influencing their availability in sediments of the studied area. The bonding of trace metals with non-mobile fractions was confirmed with the sequential extraction. Inductively coupled plasma–optical emission spectroscopy (ICP–OES) was used to measure the concentrations of the trace metals. Granulometric analyses were performed using normalized sieve apertures to determine the textural characteristics of the sediments. Enrichment factor was used to evaluate the level of metal enrichment. Heavy metals concentrations in sediment samples varied in the range: Pb (8.9–188.9 mg/kg d.w.), Zn (19.4–431.8 mg/kg d.w.), Cd (0.014–0.061 mg/kg d.w.), Ni (6.6–33.4 mg/kg d.w.), Mn (2.4–16.8 mg/kg d.w.), Cu (9.4–133.3 mg/kg d.w.), Ba (1.3–9.9 mg/kg d.w.), As (0.4–7.9 mg/kg d.w.), Co (0.9–5.1 mg/kg d.w.), Cr (1.4–7.8 mg/kg d.w.), Mg (68.8–499.3 mg/kg d.w.), Ca (11.3–64.9 mg/kg d.w.), Al (24.7–141.7 mg/kg d.w.), Na (8.8–29.4 mg/kg d.w.), and Fe (12,011–35,124.6 mg/kg d.w.). The estimated results of the enrichment factor suggested enrichments of Pb, Zn, and Cu in all the core sediment samples and depths at all sites. The other trace metals showed no enrichments in almost all the sampled stations. Continuous accumulation of Pb, Zn, and Cu metals over a period can be detrimental to living organisms and the ecology. The results obtained from the statistical analyses suggested that the deposition of trace metals in the studied sites is due to anthropogenic inputs from the adjacent land-based sources.
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    Status of pharmaceuticals in the Korle Lagoon and their toxicity to non-target organisms
    (Springer, 2022) Asare, E.A.; https://doi.org/10.1007/s10646-021-02507-1
    The availability of pharmaceutically active compounds (PhACs) in surface waters and suspended solids/sediments presents an ecological hazard of chronic exposure to non-target organisms. Thus, water and sediment samples were collected from the Korle Lagoon in the west of Accra-Ghana city center to evaluate 35 medicinal drugs belonging to the main therapeutic classes and their toxicity to non-target organisms (i.e., fish, daphnid, and algae). High-performance liquid chromatography coupled to mass spectrometry (HPLC-MS/MS) was employed to analyze the levels of PhACs in the samples. PhACs levels in water samples were higher compared to PhACs levels in sediment samples. Acetaminophen, ibuprofen, tramadol, and Diclofenac were the PhACs that showed a higher frequency of detections and higher average concentrations. Diazepam, mefenamic acid, indomethacin, gemfibrozil, and glibenclamide exhibited a higher frequency of detections, but their average concentrations in both sample types were lower. The calculated risk index values for acetaminophen and ibuprofen suggested low ecological risks to fish, while tramadol showed medium to high ecological risks to daphnid. In contrast, acetaminophen and fenofibrate showed low ecological risks to daphnid. Additionally, the risk index values for fenofibrate suggested medium to high ecological risks to algae, while tramadol exhibited low ecological risks to algae. The other PhACs showed negligible ecological risks to non-target organisms. The calculated toxic unit values for each sampled site suggested a medium adverse ecological risk to non-target organisms. Based on the results obtained, the availability of PhACs in the studied area will have adverse effects on studied non-target organisms. The negative impacts of PhACs on non-target organisms may cause an imbalance in the food chain process, leading to a decrease in fish production and a reduction in fish quality. The result of this study is evidence of public health threat because the accumulation of PhACs in fish species may also cause some kinds of hormonal, chemical, and molecular changes within the various systems of the fishes to be toxic or unpleasant for humans’ consumption.
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    Zinc Oxide Nanoparticles Synthesis Methods and its Effect on Morphology: A Review
    (2022) Droepenu, E.K.; Wee, B.S.; Chin, S.F.; Kok, K.Y.; Maligan, M.F.
    Zinc oxide is an important material with numerous applications due to its unique properties. Due to their thermal and chemical stability are used in wide applications such as LEDs, sensors, catalysts, and photodetectors. Different chemical, physical, and biological methods have been adopted to achieve the intended result, as enumerated in many pieces of literature. Therefore, selecting an efficient synthesis process is essential, which is a key factor that significantly influences the efficacy of the synthesized nanocrystalline materials. The chemical synthesis of nanoparticles (NPs) via hydrothermal, solvothermal, and sol-gel routes is considered effective as high-quality crystalline structures are produced. Control of parameters of processes yields excellent morphological features of the synthesized samples. This review explored the different parameters of processes and their effect on the morphology of ZnO nanostructures via hydrothermal, solvothermal, and sol-gel techniques. Finally, some ZnO nanocomposites molecules are reviewed as per the dopant used and its effect on the sample compound synthesized.
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    Laboratory and Commercial Synthesized Zinc Oxide Nanoparticles Adsorption onto Coconut Husk: Characterization, Isotherm, Kinetic, and Thermodynamic Studies
    (Platinum, 2021) Droepenu, E.K.; Asare, E.A.; Dampare, S.B.; Adotey, D.K.; Gyampoh, A.O.; Kumi-Arhin, E.
    The accelerating application of zinc oxide nanoparticles (ZnO-NPs) has called for attention to their potential environmental and human health risks. This work aimed to investigate the sorption efficiency of laboratory and commercial synthesized nanocrystalline zinc oxide onto raw coconut husk in a batch adsorption study. Characterization of samples was performed by employing spectroscopies techniques such as X-ray Diffraction Spectroscopy, Field Emission Scanning Electron Microscopy, Transmission Electron Spectroscopy, Fourier transform IR Spectroscopy, and Brunauer–Emmett– Teller. A spherical shaped nanocrystalline ZnO with a mean crystallite and particle size of 14.7 nm and 24 nm by XRD and TEM was synthesized as compared to the commercial ZnO-NPs of size < 50 nm. The maximum percentage removal of 88% (0.13 mg/g) and 90% (0.16 mg/g) for laboratory synthesized and commercial ZnO-NPs respectively was recorded at an optimum contact time of 80 minutes. The data also indicated 2.0 g sorbent mass and pH of 8 as the optimum conditions for maximum percentage removal of these nanoparticles. Both Langmuir and Freundlich models fitted best for laboratory synthesized ZnO-NPs with a maximum capacity of 0.797 mg/g, whereas Langmuir isotherm model alone with a maximum capacity of 0.710 mg/g fitted well for commercial ZnO-NPs. The n-value from the Freundlich model, as well as separation factor (RL) were greater than unity suggesting a favorable adsorption process. The study obeyed pseudo-second-order, which was exothermic with a high degree of freedom of sorbent-sorbate interaction. The results suggested that coconut husk is potentially scalable for removing ZnO-NPs from wastewater.