Chromium(III) removal by epoxy-cross-linked poly(ethylenimine) used as gel-coat on silica. 2. A new kinetic model

摘要

Regenerable "gel-coat" chelating resins with fast sorption kinetics and sorption selectivity have application potential for removal of trace metal ions even in large-scale operations. Poly- (ethylenimine) has been gel-coated on high surface area silica and insolubilized by cross-linking with a low molecular weight diepoxide (epoxy equivalent 180 g). The sorption of Cr(III)/SO_4~2- on this gel-coated sorbent under vigorous agitation has characteristics of particle diffusion control (pdc) with homogeneous (gel) diffusion in the resin phase.