代森铵对重金属铅镉在三峡库区消落带土壤中吸附-解吸的影响

The Effects of Heavy Metal Pb^(2+) and Cd^(2+) Adsorption-Desorption Used Pesticide Amobam in Soil of the Water-Level-Fluctuating Zone of Three Gorges Reservoir

为掌握农药代森铵存在时,三峡库区消落带土壤吸附-解吸铅镉离子的行为,采用振荡平衡法,研究了代森类农药种类、代森铵浓度、重金属离子浓度、电解质离子强度的影响.结果表明:常见代森类农药能提高土壤铅离子的吸附量,增强吸附顺序是代森锰锌>代森铵>代森锌;农药种类能减少土壤对镉离子的吸附量,抑制吸附顺序是代森锌>代森铵>代森锰锌;代森类农药能促进土壤解吸铅镉离子.土壤对铅离子的吸附量随代森铵浓度增加呈现先增加后减少,土壤对镉离子的吸附量随代森铵浓度增加而有所增加;土壤对铅离子的解吸量随着代森铵浓度增加而降低,镉离子的解吸量反而增加.代森铵存在时,土壤对铅镉离子的吸附量和解吸量随铅镉离子浓度的增加而增加;土壤对铅离子的吸附量随着电解质离子强度增加而降低,土壤对镉离子的吸附量正好相反,增加电解质离子强度,土壤对铅镉离子的解吸量逐渐增加.

To make clear the soil adsorption and desorption behavior of lead and cadmium ions when the existing amobam in Three Gorges reservoir. The effects of kinds of dithane pesticide,concentration of amobam,concentration of heavy metal ions,ionic strength of electrolyte were studied by oscillating balance method. The results showed that,the most common dithane pesticides can improve the adsorption capacity of lead ion in soil,the order of enhanced adsorption is mancozeb amobam zineb. The kinds of dithane pesticide can reduce the adsorption capacity of cadmium ion in soil,the order of inhibited adsorption is zineb amobam mancozeb,dithane pesticide can promote desorption of lead and cadmium ions in soil. Adsorption capacity of lead ion increased firstly and then decreased with the increasing concentration of amobam in soil,the adsorption amount of cadmium ion increased with the increasing concentration of amobam in soil,The soil lead ion of desorption capacity decreased with the increase of amobam concentration,the desorption amount of cadmium ion increases. The presence of amobam,The adsorption and desorption capacity of lead and cadmium ions in soil increased with the increase of lead and cadmium ions concentration,The adsorption capacity of lead ion in soil decreased with the increase of the ionic strength of electrolyte,and the adsorption amount of cadmium ion in soil was just the opposite,desorption capacity of soil lead and cadmium ions increased gradually with increasing the ionic strength of electrolyte.