Abstract
Sorptionbehavior of metal(III) phosphates toward Zn(2+) was investigated using different concentrations, pHs, and temperatures. Ion exchange between protons from the surface and metal cations from solutions was found to be responsible for metal sorption by metal(III) phosphates. Dissociation constants of metal(III) phosphates and binding constants of the Zn(2+) with metal(III) phosphates were determined using Henderson-Hasselbach and modified Langmuir equations, respectively. The sorption process in all the three metal phosphates was found to be endothermic in nature while the dissociation process was observed to be endothermic in AlPO(4) and FePO(4) and exothermic in CrPO(4). Copyright 1999 Academic Press.
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