DOWEX M 4195 and LEWATIT® MonoPlus TP 220 in Heavy Metal Ions Removal from Acidic Streams

Abstract

Two chelating ion exchangers possessing bis(2-pyridylmethyl)amine functional groups also known as bispicolylamine Dowex M4195, Lewatit® MonoPlus TP 220 were used for the selective removal of Cu(II) ions from acidic streams. The resin was characterized by CHNS elementary analysis, surface area, pore size, and volume analysis. After cutting by ultramicrotome, scans using electron microscope and optical profiler were recorded. For the first time the interiors of these resins after the sorption process were shown. Their superior binding affinities for Cu(II) was confirmed even under high acidities. Various physiochemical parameters like solution pH, ion exchange dose, presence of chloride, and sulfate ions in the system were studied in order to determine sorption capacity and kinetic parameters. The most effective chelating ion exchanger proved to be Lewatit® MonoPlus TP 220. Cu(II) ions sorption was affected by the presence of sulfate ions in the system. The monolayer sorption capacity (q0) for Lewatit® MonoPlus TP 220 was found to be 50.69 mg g−1 and 86.44 mg g−1 in the presence of chloride ions. The sorption of Cu(II) ions was found to be well represented by the pseudo second-order kinetics. The optimal desorption conditions were found using 1 M H2SO4 and 1 M NH4OH.