Preparation of MOEAMCl and MAAm Based Hydrogels and Effective Use in Anionic Dye Adsorption

In this study, hydrogels based on [2-(Methacryloyloxy)ethyl]trimethylammonium chloride (MOEAMCl) and methacrylamide (MAAm) were synthesized for the removal of anionic dyes from aqueous solutions. Following detailed characterization, the use of hydrogels for methyl orange (MO) adsorption was investigated. Hydrogels prepared at MOEAMCl-MAAm monomer feed ratios of 75:25 and 50:50 (HD-2 and HD-3) were found to be effective in MO removal. The optimal pH for MO adsorption was determined to be 9, the adsorption time 6 h, and the amount of adsorbent 0.1 g. Under optimal adsorption conditions, dye removal at an MO concentration of 1000 ppm was 89.4% and 90.9% for HD-2 and HD-3 hydrogels, respectively, with adsorption capacities of 950 and 994 mg/g. It was observed that MO adsorption on both hydrogels decreased with increasing adsorbent amount and temperature, but was almost unaffected by the medium matrix. Additionally, the Freundlich isotherm was found to be the appropriate isotherm model, and kinetic results indicated that the HD-3 hydrogel fit all examined kinetic models better than HD-2. In conclusion, it was determined that these adsorbents could be efficiently used for anionic dye removal.