Preparation of poly(vinyl alcohol)/tetraethyl orthosilicate hybrid membranes modified with TMPTMS by sol-gel method for removal of lead from aqueous solutions

摘要

Poly(vinyl alcohol)/tetraethyl orthosilicate (PVA/TEOS) ion exchange hybrid membranes modified with 3-mercaptopropyltrimethoxysilane (TMPTMS) were prepared by the sol-gel method, and their applications for the removal of lead ions from aqueous solutions in a batch sorption process were studied. The functional groups of the hybrid membranes were characterized by FITR. Batch adsorption studies such as TMPTMS content, pH, adsorbent dose, contact time, initial concentration and temperature were evaluated. The maximum adsorption capacity of lead ions was found to be 61.62 mg g~(-1), respectively. The kinetic data were analyzed by pseudo-first-order and pseudo-second-order kinetic models. The Freundlich and Langmuir isotherm models were applied to describe the equilibrium data. Thermody-namic parameters indicated that the lead adsorption onto the membrane is an endothermic and spontaneous process. The PVA/TEOS/TMFTMS hybrid membrane is regenerated by 0.5 M HNO_3/0.1 M HC1 in equal ratio solution and the adsorption capacity did not change remarkably after five sorption-desorption cycles.