L. Valiente Instituto Nacional de Tecnología Industrial, Argentina

S. Korfali Department of Chemistry, Lebanese American University, Lebanon

ABSTRACT: Two approaches have been investigated for the removal of arsenic speciation from water. The first involved the modification of diatomaceous earth (diatomite) using ferric oxide, which increased the uptake of arsenite and arsenate compared to raw diatomite. The kinetics of arsenic sorption was studied and increased through heat treatment prior to Fe modification. Temperature was found to have minimal effect on arsenic kinetics while significant changes on As uptake were observed with increasing pH. Additionally, high matrix waters (tap & spring) have minimal effect on arsenate uptake but a larger effect on arsenite sorption was identified. The three forms of interest; raw, calcined and modified diatomite were successfully characterized by multiple techniques. The second approach included the application of macrocyclic receptors based on calix[4]pyrrole and its dimer for the removal of arsenic speciation from water. The optimum conditions for the extraction process were investigated and compared to polypyrroles.