Study on the Adsorption Performance of Biochar/Montmorillonite Composites for Ciprofloxacin Hydrochloride

Abstract In response to the widespread and difficult-to-treat phenomenon of antibiotic pollution by ciprofloxacin hydrochloride, this study has chosen to adopt a simple and efficient adsorption method for its treatment and innovatively proposed a method for preparing biochar/montmorillonite composites through pyrolysis and intercalation methods for adsorption treatment. The study also analyzes factors affecting the adsorption effect as well as the adsorption thermodynamics and kinetics characteristics, aiming to provide new efficient and low-cost technologies and ideas for the treatment of antibiotic wastewater. And the research indicates: a) Compared to single biochar and montmorillonite, the specific surface area of biochar/montmorillonite composites has significantly increased, with C2M1C reaching 246.729 m2.g-1, which is 91% higher than ZBC. The reason is that the composite material’s surface has both the layered structure of montmorillonite and the tubular pore structure of biochar. b) The optimal ratios for preparing composites by pyrolysis and intercalation methods are 1.5:1 and 2:1, respectively, and composites prepared at these ratios exhibit the best adsorption effect for CIP. c) Composite materials are more suitable for CIP adsorption in alkaline environments (with an optimal pH value of 10). d) The adsorption capacity of CIP increases with time, initial concentration, and temperature. e) The adsorption capacity of composite materials for CIP decreases significantly with an increase in the number of cycles. The adsorption amounts of materials R1.5M1D and intercalated composite material C2M1C dropped from 89.457 and 114.782 mg g-1 during the first cycle to 16.237 and 24.353 mg g-1 in the fifth cycle, with decreases of 81% and 78%, respectively.