Response surface methodology-based modeling and optimization of fenugreek gum-based hydrogel for efficient removal of malachite green dye

This research work describes the synthesis of a fenugreek gum (FG)-based hydrogel (FG-g-poly(AAm)) via free radical polymerization for the removal of malachite green (MG) dye from an aqueous solution. The effects of various parameters such as backbone amount, initiator, monomer, cross-linker, and solvent on the percentage swelling were investigated using a 2-level-5-factor central composite half fraction design as an experimental design for response surface methodology. The model was found to be significant with a maximum percentage swelling of 1360%. The formation of a crosslinked network was validated by FTIR, TGA, XRD, BET, and FE-SEM characterization techniques. The surface area and average pore radius of the prepared FG-g-poly(AAm) were found to be 0.695 m2/g and 18.124 & ANGS;, respectively. The synthesized FG-g-poly(AAm) hydrogel was examined for the adsorption of MG dye from an aqueous solution as a function of time, pH, adsorbent dose, initial dye concentration, and temperature. The prepared hydrogel showed a maximum sorption capacity of 585 mg/g, as confirmed by pseudo-2nd-order kinetic and Langmuir adsorption models, revealing adsorption's chemisorption nature. The positive values of & UDelta;Ho and & UDelta;So showed that an endothermic process accompanied the adsorption process and had an affinity for dye molecules. The synthesized hydrogel can be used as a candidate for cationic dye removal.