Preparation of Zeolite‐g‐Polyacrylamide using Radiation Induced Grafting and Its Adsorption Isotherms Study on Several Heavy Metal Ions

Zeolite‐g‐polyacrylamide is prepared by using the radiation induced grafting technique. Clinoptilotite, a natural zeolite, is used as the base matrix. In order to increase the degree of grating of polyacrylamide into the zeolite, its surface is modified with silane compound before the grafting reaction and applied a poor solvent method in the grafting reaction, i.e., a mixture of toluene and H2O. The irradiation doses are varied from 10 to 50 kGy. The grafting parameters are 40% w/w acrylamide, temperature 60 °C and 3 h grafting time. The highest degree of grafting is 93% at an irradiation dose of 25 kGy. The zeolite‐g‐polyacrylamide is then characterized with FTIR spectroscopy and SEM observation. Batch experiments are also carried out to investigate the adsorption capacity for ion Cr3+, Pb2+, and Zn2+. The maximum adsorption capacities of zeolite‐g‐polyacrylamide are 544, 345, and 1046 mg g−1 for ion Cr3+, Pb2+, and Zn2+, respectively. The equilibrium data are also tested with Langmuir and Freundlich isotherm to find the best suitable adsorption isotherm system.