Fabrication of sulfur-doped biochar derived from tapioca peel waste with superior adsorption performance for the removal of Malachite green and Rhodamine B dyes

Abstract

The rapid industrialization and explosion of the population result in increased usage of water and its consequent discarding causes environmental pollution. The biochar based materials are effectively employed for the removal of dyes from contaminated water. However, the pristine biochar shows less efficiency towards dye adsorption in practical applications. Herein, sulfur tethered adsorbent of Tapioca peel (S@TP) biochar was successfully fabricated and utilized for the removal of organic dyes such as Malachite Green (MG) and Rhodamine B (RhB) from water. The peel of tapioca was used as a precursor for the biochar preparation. The isotherm analysis demonstrates that the S@TP biochar has the adsorption efficiency of 30.18 and 33.10 mg/g for MG and RhB dye molecules, respectively. 25 mg/L concentration of 50 mL dye solutions were used for the adsorption study. The maximum adsorption was observed at a pH range ~8, and the adsorption attained saturation within 120 min. The adsorption followed the pseudo-second-order kinetics, and the adsorption process was composed of the Freundlich isotherm model. The newly fabricated adsorbent could be utilized as a capable adsorbent for the water/wastewater treatment process. The newly fabricated bio-mass could be visualized as a capable adsorbent for water/wastewater treatment process since the S@TP matrix possesses high removal and reusable efficiency towards dye molecules.