Optimization of Hazardous Malachite Green Dye Removal Process Using Double Derivatized Guar Gum Polymer: A Fractional Factorial L9 Approach

The dye molecules are one of the water-polluting agents among other contaminants in water bodies and impart unsuitability. In recent years, bio-based materials have attracted considerable attention for varied industrial applications due to their abundant availability on a sustainable basis, biodegradability, cost and energy efficiency. The present study hypothesized to synthesize carboxymethyl-hydroxypropyl guar gum (CMHPGG) dual derivative to remove malachite green dye from an aqueous medium using Taguchi's L9 design. The 73 % dye adsorption was achieved using CMHPGG, comprising carboxymethyl (DS 0.58) and hydroxypropyl (0.128 %) groups. The temperature, pH of the medium and amount of CMHPGG were selected as dye adsorption process control factors. The optimized reaction conditions comprise pH 5, CMHPGG-2, 250 mg/100 mL, and a temperature of 45°C. The characteristic asymmetric (1643 cm−1) and symmetric (1590 cm−1) absorption bands (-COO¯) were observed in the CMHPGG. The roughness was observed on the surface that was increased on derivatization. The thermal behaviour revealed better thermal stability compared to native GG.