Removal of acid dyes from wastewater using poly(acrylamide-vinylimidazole) hydrogel

In this study, the removal of acidic dyestuff, Acid Blue 193 (Isolan Dark Blue 2S-GL-03) from the aqueous solution by using the newly synthesized poly (Acrylamide-Vinimidimidazole) (poly (AAm-VI)) hydrogel in the batch system was investigated by adsorption. The synthesized hydrogel was characterized by SEM, FTIR and TGA methods. The effects of the initial concentration of dyestuff, initial pH value of solution, hydrogel dosage, contact time and stirring speed on the adsorption process were studied. It was determined that the amount of the adsorbed dyestuff increased when hydrogel dosage increased. The maximum adsorption was observed to occur at pH 1.5. While the initial solution concentration, initial pH value, contact time, stirring speed, and hydrogel dosage were 250 mg/L, 1.5, 90 minute, 600 rpm, and 2 g/L, respectively, the efficiency of dye adsorption on hydrogel was 99.8%. Langmuir, Freundlich, Temkin and Dubinin-Radushkevich adsorption isotherms were used to express the relationship of dyestuff with poly (AAm-VI) hydrogel and kinetic analyzes were performed. The correlation coefficient (R2) was used as an indicator of the best model fit of the different models and it was determined that the equilibrium data fit the Freundlich isotherm model and the pseudo second order kinetic model which have large R2 values. The results showed that poly (AAm-VI) hydrogel could be used as a suitable sorbent to remove acidic dyes from contaminated water.