【摘要】 以板页岩母质土壤黄泥田和第四纪红壤母质土壤红黄泥为研究对象,通过老化试验和解吸试验研究草酸、柠檬酸对不同母质土壤中Cd的解吸作用及影响机制。结果表明:黄泥田中Cd的存在形态较红黄泥更易迁移或被利用。随有机酸添加量增加,土壤pH降低,Cd的解吸作用增强。有机酸种类对土壤Cd解吸行为的影响也存在一定差异。去除土壤有机质可以通过改变土壤基团种类和含量影响Cd²⁺与土壤表面之间的相互作用进而影响Cd的解吸。综合以上结果可知,外源有机酸主要通过影响土壤溶液pH、有机配体与土壤表面及Cd²⁺的络合反应来影响Cd的解吸,土壤母质类型及其理化性质是影响外源有机酸对土壤中Cd解吸行为的重要因素。更多还原

【Abstract】 Yellow clayey soil developed from plate shale and red yellow soil developed from quaternary red clay were selected to investigate the desorption effects and the influence mechanisms of oxalic acid and citric acid on soil Cd in different parent soils using aging and desorption experiment.The results show that the speciation of Cd in yellow clayey soil are more likely to migrate or be used compared with red yellow soil.With the increasing of organic acid content,p H value of the soils decreases,and the desorption of Cd is enhanced.The effects of different types of organic acids on the desorption behavior of Cd in soil are also different.The removal of organic matter in soils can promote the desorption effect of organic acid on soil Cd though changing the reactions between Cd²⁺ and soil surface groups.Based on the results above,exogenous organic acids affect Cd desorption mainly by affecting the p H value of soil solutions and the complexation reaction between organic ligands and soil surface and Cd²⁺. The type of soil parent material and its physicochemical properties are important factors affecting the desorption behavior of exogenous organic acids on Cd.更多还原