Factors study for the removal of epoxiconazole in water by common biochars

Biochar has acquired increasing attention in waste utilization and the treatment of environmental pollutants. In this study, the physicochemical properties of five types of biochars include straw biochar (SWB), coconut shell biochar (CSB), sawdust-coal biochar (SCB), bamboo biochar (BOB), rice husk biochar (RHB), and their adsorption of epoxiconazole (EPC) is discussed. The effects of initial concentration of EPC, solution temperature and pH level to these biochars were investigated. Besides, this work also analyzed the adsorption kinetics, adsorption isotherm, and thermodynamics of EPC removal in five biochar. Freundlich isotherm shows that the adsorption capacity decreased in the order SCB > BOB > CSB > SWB > RHB. The removal efficiency of EPC by SCB, BOB and CSB are much higher than SWB and RHB, and SCB has the best performance in EPC removal. The adsorption capacity of SCB is 19.0 g/kg, and its removal rate is nearly 97 %. The adsorption capacity of RHB is only 10.8 g/kg, with the removal rate of about 51 %. According to the characterization results of BET, SEM, XRD, and FT-IR, it is speculated that the adsorption capacity of five biochars to EPC is closely related to the total pore volume and specific surface area (SSA).