【摘要】 研究了三个可变电荷土壤吸附磷酸根后对Cu、Zn、Cd次级吸附和解吸的影响。结果表明,供试土壤对重金属的次级吸附等温线符合Langmuir方程,次级吸附量的大小顺序是,湖北孝感黄棕壤>湖北咸宁红壤>湖南桃源红壤。土壤吸附磷酸根后,可使重金属的次级吸附量增加,解吸率下降,并有线性关系。供试土壤吸附磷酸根后,表面负电荷增加,表面负电荷的增量与重金属次级吸附量的增量呈线性关系,这表明土壤吸附磷酸根后,表面负电荷的增加,可能是影响重金属次级吸附的重要原因之一。更多还原

【Abstract】 The effect of phosphate absorption on Cu, Zn, Cd secondary adsorption and desorption in three variable charge soils was studied. The results showed: the isotherms of heavy metal secondary adsorption by soils were fitted for Langgmuir equation ,the amounts of secondary adsorption were in order: yellow brown siols in Xiaogan Hubai>red soil in Xianning Hubai>red soil in Taoyuan Hunan. The adsorption of phosphate by soil resulted in the increase in the amount of heavy metal secondary adsorption and the decrease of desorption percentage. The relation between adsorption of phosphate and the amount of heavymenal secondary adsortion, the percentage of desorption was in line. When l cmol P was absorbed, the amount of heavymetal secondary adsorption increased 0.0177--0.2266 cmol, the percentage of desorption decreased 2.95--5.46%. After the phosphate was adsorbed, the surface negative charge increased, moreover, the relation between the increased amount of surface negative and the amount of heavy metal secondary adsorption was in line. This indicated that the increase of surface negative was probably one of the most important phosphate was absorbed.更多还原