The application of poly-(acrylamide) hydrogel prepared by gamma irradiation for methylene blue adsorption in aqueous solution

The aim of the research is to study the capacity of poly(acrylamide)(PAAM) hydrogel to adsorb a synthetic dye of methylene blue (MB). PAAM hydrogel was synthesized by varying gamma radiation doses (20-40 kGy), and was then processed to dried powder (120 mesh) and used to adsorb MB dye from the aqueous solution. The batch adsorption experiment was carried out by varying contact time (0-120 min.), initial concentration of MB (2-10 mg/L), adsorbent dose (0- 120 mg), and the chemical changes of hydrogels were characterized by Fourier Transform infra red (FTIR). The adsorption process of MB was examined with Langmuir and Freundlich isotherm models. The results showed that the hydrogel prepared at 20 kGy had higher adsorption capacities onto MB compare to the hydrogel at 30 and 40 kGy. With increasing hydrogel doses, the MB adsorbed increase. The results of Langmuir and Freundlich isotherm examination obtained the coefficient correlation (R²) of 0,9914 and 0,9964 with maximum adsorption capacity 1.67 mg/g at a solution pH of 6.5. Modification of PAAM hydrogels will be potentially as dyes adsorbent. (author)