Abstract:
In this work, bagasse, an agricultural waste was used for the development of environmentally benign biochar (CBG) and the thermal pyrolysis product applied for adsorption of sulfamethoxazole (SMX) from water using a batch technique. The
pseudo-first-order model best described the adsorption kinetics. Equilibrium adsorption data were modelled using six two parameter and five three-parameter isotherm equations and the best-fitting models obtained using five error functions. The Sips
isotherm best predicted the equilibrium data with an estimated adsorption capacity of 128.8 mg g–1. Error analysis showed that three-parameter isotherms best explained the experimental data. The thermodynamic functions, viz. enthalpy (ÄH = –24.72 kJ mol–1), Gibbs free energy (ÄG = –15.67 kJ mol–1), entropy (ÄS = 32.65 kJ mol–1), showed that the reaction is spontaneous and exothermic. The mechanism of adsorption involved charge-assisted hydrogen bonding (-)CAHB. The amount of CBG required for the removal of 99 % of SMX in a given volume of effluent was predicted. The results attest that CBG is an effective low-cost adsorbent for SMX adsorption.
