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研究了不同温度下制得的生物炭对西北黄土吸附农药克百威的影响,并对溶液p H值和初始浓度对吸附的影响进行了探讨.结果表明,克百威在添加生物炭黄土上的动力学吸附过程较好地符合准二级吸附动力学模型;热力学吸附较好地符合Freundlich等温吸附模型;随着系统温度的升高,添加生物炭的黄土对克百威的吸附量增大,且其对克百威的吸附自由能变(ΔGθ)小于0,吸附焓变(ΔHθ)及吸附熵变(ΔSθ)均大于0,表明吸附是一个自发吸热且体系混乱程度增大的等温吸附过程.溶液p H值和克百威的初始浓度对添加生物炭的土样吸附影响较明显.当p H值为4~7时,添加生物炭的土样饱和吸附量随p H升高呈缓慢降低,当p H值大于7时,吸附容量随p H升高呈明显降低趋势.克百威初始浓度从20 mg·L-1增至50 mg·L-1的过程中,吸附量快速上升,初始浓度大于50 mg·L-1时,吸附量随初始浓度的升高而缓慢增加并逐渐趋于平衡.
The effects of biochar prepared at different temperatures on the adsorption of carbofuran in the northwestern loess were studied, and the effect of pH value and initial concentration on the adsorption was studied. The results showed that the adsorption of carbofuran on biochar loess Kinetic adsorption process is in good agreement with quasi-second-order adsorption kinetics model; thermodynamic adsorption is in good agreement with the Freundlich isothermal adsorption model; with the increase of system temperature, the adsorption capacity of carbofuran to biochar is increased , And its adsorption free energy (ΔGθ) to carbofuran is less than 0, and the enthalpy change (ΔHθ) and entropy change (ΔSθ) are all greater than 0, indicating that the adsorption is an isothermal spontaneous endothermic and system chaos increase Adsorption process.The p H value of the solution and the initial concentration of carbofuran had a significant effect on the adsorption of soil samples with the addition of biochar.The saturated adsorption capacity of soil samples with biochar increased from p H up to 4 When the p H value is greater than 7, the adsorption capacity decreases obviously with the increase of p H. In the process of increasing the initial concentration of carbofuran from 20 mg · L-1 to 50 mg · L-1, the adsorption capacity When the initial concentration was more than 50 mg · L-1, the amount of adsorption increased with the initial concentration Slowly increase and gradually tend to balance.