Pectin-Tin(IV) molybdosilicate: An ecofriendly cationic exchanger and its potential for sorption of heavy metals from aqueous solutions

A novel composite cation exchanger of biopolymer Pectin and Tin(IV) molybdosilicate heteropoly acid salt were prepared by co-precipitation technique. Physico-chemical characterization of Pectin-Tin(IV) molybdosilicate was performed using instrumental techniques such as FTIR, TG, XRD and SEM-EDS. Studies were carried out to investigate ion exchange capacity. pH titration carried out shows cationic nature and polyfunctionality of the exchanger. Distribution coefficients of various metal ions were done to explore the ion exchange behavior of cation exchanger. Distribution studies show that the material is highly selective for toxic heavy metal ions such as Cd2+, Cu2+, Al3+ etc. To investigate the environmental applicability of the exchanger some analytically important binary separations and selective separation of metal ions from industrial effluents were achieved. Kinetic and isotherm parameters were evaluated to predict the mechanism of sorption of heavy metal ions. Mass transfer analysis shows that internal particle diffusion and some degree of boundary layer control the sorption process.