草木灰污泥联合施用对Cd污染土壤中Cd形态变化的影响

Effects of Straw Ash and Sewage Sludge on Morphologic Changes of Cadmium in Cadmium Contaminated Soil

利用盆栽小白菜试验研究了施入草木灰、污泥和草木灰污泥混合物对镉污染土壤中Cd形态的影响。结果表明:草木灰、污泥和草木灰污泥混合物的施用导致了土壤中Cd的重新分配;土壤中生物有效性较高的有效态Cd含量明显降低,并转化为不易被植物吸收的惰性态Cd。土壤水溶态和交换态Cd含量较对照最大降低56.60%～68.38%;有机结合态Cd含量显著升高,最大升幅较对照升高166.7%～281.1%;无机结合态Cd最大升幅达72.60%～73.20%,残渣态Cd含量较对照升高,最大升幅为37.93%～112.50%。因此,可以通过施入草木灰、污泥、草木灰污泥混合物来修复Cd污染土壤。

Effects of straw ash and sewage sludge on the morphologic changes of cadmium in cadmium contaminated soil were investigated with potted cabbage.The results showed that application of straw ash,sewage sludge can lead to the redistribution of Cd in soil.Application of straw ash,sewage sludge converted soluble and exchangeable Cd in the soil into inertia and organic-bound Cd.The concentration of soluble and exchangeable Cd was decreased 56.60%-68.38%,and organic-bound fraction was increased 166.7%-281.1% in comparison with the control.Inorganic-bound Cd was significantly increased with the largest increase of 72.60%-73.20%.Residual Cd increased 37.93%-112.5% in comparison with the control.Therefore,straw ash and sewage sludge can be applied to repair Cd contaminated soil.