Preparation and characterization of super-adsorbent containing functional groups in one step and application of a model cationic dye removal

In this study, super adsorbent in hydrogel structure carrying functional -SO3H group was synthesized in one step using the 2-hydroxyethyl methacrylate (HEMA) and 2-acrylamido 2-methyl-1-propanesulfonic acid (AMPSA) monomers in different ratios. The adsorptive property of the prepared p(HEMA-AMPSA) hydrogel was tested for Crystal Violet (CV) and Congo Red (CR) dyes selected as model dyes. The effect of various system parameters such as media pH, contact time, initial dye concentration, temperature, and amount of adsorbent used on the adsorption of CV and CR dyes using the p(HEMA-AMPSA) hydrogel was investigated. Scanning electron microscopy, zeta-sizer, BET (Brunauer, Emmett and Teller) method and ATR-FTIR spectroscopy were used for the characterization of p(HEMA AMPSA) hydrogels. In the process of removing CV and CR dye from aqueous media with p(HEMA-AMPSA)-2 hydrogel particles, the maximum adsorption capacity at 25 oC was found to be 306,1 mg/g and 186,9 mg/g respectively. The R2 values greater than 0,989 obtained for both dye removals of p(HEMA-AMPSA)-2 hydrogel particles showed the applicability of the Langmuir isotherm model. The calculated RL values of the p(HEMA AMPSA)-2 hydrogel particles ranged from 0,003 to 0,094 and 0,008 to 0,107 for CR and CV, respectively, indicating that the prepared hydrogel was suitable for model dyes. The adsorption capacity of CR and CV dyes adsorbed on hydrogel particles increased by 2,1 and 2,3 times, respectively, by increasing the ambient temperature from 15 ℃ to 45 ℃.