咖啡渣生物炭的制备及其对水体中拟除虫菊酯农药的吸附机理研究

Preparation of coffee residue⁃based biochar and study on its adsorption mechanism for pyrethroid insecticide in water

以咖啡渣为原料制备生物炭,研究不同温度下其对4种拟除虫菊酯类农药的吸附机理。对不同温度制备的生物炭的理化性质及表面性质进行研究;通过吸附效率实验选取最佳制备温度,再进行吸附动力学实验和等温吸附实验。实验结果表明,800℃为最佳制备温度,此时生物炭的吸附性能和芳香性更强,表面孔隙多,形变程度大;800℃制备的生物炭对拟除虫菊酯农药的吸附更符合准一级动力学模型,而吸附热力学过程更符合Freundlich模型。吸附热力学参数表明,800℃制备的生物炭对4种拟除虫菊酯农药的吸附均为自发的吸热过程。

Biochar is made from coffee residue,and its adsorption mechanism on four kinds of pyrethroid insecticides is studied at different temperature.Firstly,the study is performed on the physicochemical and surface properties of biochar prepared at different temperature.Through adsorption efficiency experiments,the optimal preparation temperature is selected,followed by adsorption kinetics and isothermal adsorption experiments.Experimental results show that 800℃is the optimal preparation temperature.Biochar prepared at 800℃exhibits stronger adsorption performance and aromaticity,possesses more surface pores,and shows greater deformation degree.The adsorption of pyrethroid insecticides by biochar made at 800℃is more in line with the quasi first order kinetic model,while Freundlich model can better describe the adsorption thermodynamic process.The adsorption thermodynamic parameters indicate that the adsorption of four kinds of pyrethroid insecticides by biochar made at 800℃is a spontaneous endothermic process.