Removal of Pb~(2+) Ions from Water by Poly(Acrylamide-co-Sodium Methacrylate) Hydrogels

摘要

The application of poly(acrylamide-co-so-dium methacrylate) (AAm/SMA) hydrogel for the removal of Pb~(2+) ions from aqueous solutions has been investigated using batch adsorption technique. The extent of adsorption was investigated as a function of pH, adsorbent dose, and temperature. The Fourier transform infrared (FTIR) spectra showed that -NH_2 and -COOH groups are involved in Pb~(2+) ion adsorption. The obtained results were analyzed by pseudo-first-order, pseudo-second-order, and intraparticle diffusion models using both linear and nonlinear methods. It was found that the Pb~(2+) ion adsorption followed pseudo-first-order kinetics. Nonlinear regression analysis of six isotherms, Langmuir, Freundlich, Redlich-Peterson, Toth, Dubinin-Radushkevich, and Sips, have been applied to the sorption data, while the best interpretation was given by Redlich-Peterson. Based on the separation factor, R_L, the Pb~(2+) ion adsorption is favorable, while the negative values of AG indicates that the Pb~(2+) ion adsorption on the investigated hydrogel is spontaneous.