Enhancement of As() adsorption from aqueous solution by a magnetic chitosan/biochar composite

In this study, a magnetic chitosan/biochar composite (MCB) was prepared successfully, and characterized by SEM, TEM, VSM, XRD, FTIR, XPS, and zeta-potential to obtain its physical and chemical properties. The influence of different sorption parameters such as pH, contact time, initial As( v ) concentration, and temperature on As( v ) removal were studied thoroughly in order to optimize the reaction conditions. The results showed that the MCB adsorbed more As( v ) (11.961 mg g −1 ) than pristine biochar (3.681 mg g −1 ). In addition, the adsorption behavior could be well described by a pseudo-second-order and Langmuir model. Thermodynamic parameters revealed that the sorption reaction was a spontaneous and endothermic process. The adsorbed MCB could be effectively regenerated by 1.0 mol L −1 NaOH, and the adsorption capacity decreased from 11.823 to 8.078 mg g −1 in five cycles. In conclusion, MCB could be used as an efficient adsorbent for environment purification and conveniently separated from aqueous solution after adsorption. In this study, a magnetic chitosan/biochar composite (MCB) was prepared successfully, and characterized by SEM, TEM, VSM, XRD, FTIR, XPS, and zeta-potential to obtain its physical and chemical properties.