粉煤灰和石灰对突发性污染土壤中重金属化学形态的影响

利用石灰和粉煤灰对突发性污染土壤中重金属进行修复,采用TCLP法和Tessier浸提法对修复后土壤进行评价。结果表明,当石灰用量为土重的0.1%时,培养1个月,突发性污染土壤中Cu、Cd浸提量(TCLP法)比对照分别下降68.13%和76.67%;当粉煤灰用量为土重的8%时,土壤Cu、Cd浸提量比对照分别下降61.58%和71.67%。两种土壤经修复后,Cu、Cd浸提量均降至国际标准值以下,原因是施用粉煤灰和石灰后,土壤中Cu、Cd的形态由交换态向碳酸态和铁锰态发生转化。

Effect of lime and fly ash on chemical forms of heavy metal in sudden polluted soils

Heavy metal of sudden polluted soil was fixed by lime and fly ash,the content of heavy metal were analyzed by the TCLP and Tessier form for evaluation of heavy metal pollution in soil.The results indicated that compared with the control,the treatment with 0.1% lime addition could significantly decrease the concentrations of Cu and Cd after 1 months incubation(68.13%,76.67% decrease for Cu and Cd,respectively) by TCLP method.The treatment with 8% fly ash addition could significantly decrease the concentrations of Cu and Cd at the same condition.And the leaching contents of Cu and Cd were lower than the threshold of the standard,after adding the amendments to the polluted soil,the main reason is that the content of exchangeable Cu and Cd turns to carbonate and Fe-Mn oxide Cu and Cd.