Performance evaluation of sugarcane bagasse biochar based fixed bed column for removal of triclosan from aqueous solution in presence of humic acid: Mechanism, kinetics and safety

Abstract

Triclosan (TCS), an emerging pollutant emerges as a notable contributor to adverse impacts on aquatic organisms owing to its widespread use during COVID19. The current study aims to investigate the efficiency of sugarcane bagasse biochar (SBB) for removal of triclosan (TCS), an emerging pollutant in aquatic ecosystems in presence of humic acid from aqueous solution through batch and column studies. In batch study, SBB prepared at pyrolysis temperature of 400 °C showed highest adsorption of TCS. Langmuir isotherm model showed highest adsorption of 68.49 mg g−1 at pH 7.0. A 90 % reduction in TCS was accomplished with 0.625 g L−1 of SBB-400 °C. Adsorption kinetic modelling was well fitted to pseudo-second order model signifying that rate of adsorption on SBB-400 °C mainly depends on chemisorption. TCS removal was not significantly inhibited in presence of 5, 10 and 25 mg L−1humic acid concentrations. Column experiments of continuous flow biochar-bed column with the aqueous solution spiked with TCS (100 mg L−1) at a flow rate of 50 mL min−1 showed 99 % removal efficiency. Thomas model and Yoon-Nelson model signified the breakthrough behaviour of TCS adsorption on the column and the experimental data were in good agreement with the expected values. Bioassay studies on Chlorella vulgaris exhibited that percentage inhibition (8 %) in algal cell counts was significantly less in the SBB treated TCS water when compared with control (untreated water containing TCS). The designed column is highly efficient, effective and eco-friendly approach for TCS removal.