Removal of sulfamethoxazole and methylparaben using hydrocolloid and fiber industry wastes: Comparison with biochar and laccase-biocomposite

In this study, the application of hydrocolloid and fiber industry wastes and their transformation in biochar and biocomposite as biosorbents for emerging pollutants effective removal was carried out. Initially, the adsorption ability of six different wastes was ascertained in single and competitive removal of sulfamethoxazole (SMX) and methylparaben (MePa). Among them, fiber extraction process wastes presented the best result attaining maximum uptakes with removal levels up to 23 and 48% of MePa and SMX, respectively. The adsorption capacity was enhanced by fiber waste biochar preparation at 500 °C and 30 min under nitrogen atmosphere, and improved by the preparation of laccase-biocomposites, achieving maximum uptakes more than ten-fold the obtained using raw material. The simultaneous removal of the pollutants by the biocomposite followed a pseudo-second order kinetic and resulted in maximum uptakes of 24.06 and 23.15 mg/g for SMX and MePa, respectively. Finally, raw material and laccase-biocomposite behaviours were simulated by homogeneous surface diffusion model. Previously, the isotherms were studied fitting well to Freundlich model. The obtained results remarked the feasibility of laccase-biocomposite in which reactive groups incorporation on the biochar surface could be responsible for facilitating the pollutants removal from the aquatic environment.