Article ID Journal Published Year Pages File Type
4486605 Water Research 2006 7 Pages PDF
Abstract

The removal of divalent metal ions from hard waters or galvanic wastewater by polymer-assisted membrane filtration using alginate was investigated. The ability of this natural polymer to form aggregates and gels in presence of metal ions was studied, in order to carry out metal removal by ultra or micro-filtration. Alginate titrations have shown the presence of amine groups in addition to carboxylates onto the polymer backbone. The binding properties of alginate with divalent cations have been studied, showing an increasing affinity for Ca2+ over Mg2+ as polymer concentration increases, and the relative affinity Pb2+⩾Cu2+>Zn2+>Ni2+. The softening of hard natural waters was achieved successfully and easily, but needs an optimal alginate concentration ∼4×10−2 M. The alginate powder can be directly added to hard waters. Except for Ni2+, metal-removal was efficient. Polymer regeneration has shown that Cu2+-complexes are labiles.

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Physical Sciences and Engineering Earth and Planetary Sciences Earth-Surface Processes
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