| Abstrakt: |
Watermelon rind biochar (WM) prepared by pyrolysis was used to adsorb Zn2+ in water, and then pyrolyzed again to prepare biochar adsorbent (WM-Zn). WM-Zn was used to adsorb Pb2+ (WN-Zn-Pb) in water. The adsorption capacity of WM-Zn for Pb2+ (163.84 mg/g) was higher than that of WM (87.64 mg/g). The biochar was characterized by XPS, FTIR, EA, XRD, BET, and Zeta. The results showed that the expansion of the surface pore structure of WM-Zn and the increase of functional groups all contribute to the removal of Pb2+. It was found that the adsorption of Pb2+ by WM-Zn can be attributed to functional group complexation, electrostatic adsorption, physical adsorption and precipitation. In addition, WM adsorption of Zn2+ and WM-Zn adsorption of Pb2+ were in line with the Langmuir isotherm adsorption model and the pseudo-second-order kinetic model, which indicated that the adsorption process was chemical adsorption based on monolayer adsorption. In the adsorption-desorption cycle experiment, the adsorption amount of WM-Zn in the sixth cycle reached 87.36 mg/g, indicating that WM-Zn had good recoverability. [ABSTRACT FROM AUTHOR] |
