dc.description.abstract |
An “ionic barrier” concept is proposed to introduce selectivity function to adsorbents towards precious
metals (PMs) in the present study. As a model system, melamine-impregnated alginate capsule (MIAC)
was prepared and used as a Pd(II) selective adsorbent from a binary metal solution containing Pt (IV) and
Pd(II). The MIAC exhibited excellent Pd(II) selectivity for a pH around 4.3, where the selectivity coefficient
reached a high value of 2190.66. In comparison to the very low Pt (IV) uptake, a high maximum
uptake of Pd(II) was estimated of 316.92 ± 9.50 mg/g by the Langmuir isotherm model. Sorptiondesorption
studies showed that the MIAC had a good reutilization property. The selective process for
Pd(II) recovery was proposed as follows: the electroneutral Pd(OH)2 but not anionic PtCl5
first penetrate
the outer ionic barrier; then, the penetrated Pd(OH)2 was bound by the inner melamine through chelation.
The ionic barrier-based sorbent thus can be considered as an alternative one for separation and
recovery of Pd(II). |
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