【摘要】 在汞污染土壤中添加不同种类型生物质炭,研究生物质炭对土壤中有效态汞含量的影响.并通过生物炭对汞离子的吸附动力学模型、等温吸附拟合和吸附前后红外光谱图的变化,探讨不同生物质炭对土壤中汞的吸附行为和机理.实验结果表明,土壤中添加生物炭后,土壤中有效态汞含量显著降低,降低比例达到77.5%—87.1%;而通过生物炭吸附汞离子前后的红外光谱图分析可知,生物炭对汞的吸附主要是通过羟基、羧基和酰胺等含氧酸官能团等.此外,吸附动力学结果显示,生物炭对汞离子的吸附时间在150 min内就可以达到平衡.而准二级动力学方程结果表明,这种吸附是以化学吸附为主.更多还原

【Abstract】 Five different types of biochar were applied to mercury contaminated soil to investigate their impacts on the available mercury in soil. Meanwhile, the adsorption kinetics, adsorption isotherms of mercury ions on biochar and the change of Fourier transform infrared(FTIR) spectra were also investigated in an attempt to understand the adsorption mechanisms of Hg by biochar. The results showed that the available mercury in soil decreased significantly and the ratio reached 77.5%—87.1% after addition of biochar in the soil. The difference of FTIR spectra of biochar before and after the adsorption indicated that hydroxyl group, carboxyl group and amides group may be the major adsorptive sites for Hg(Ⅱ) on the surface of the biochar. In most cases, the adsorption of Hg(Ⅱ) by biochar reached balance within 150 mins and the adsorption was mainly through chemical adsorption, and it fits pseudo-second-order model.更多还原