复合矿化稳定剂对土壤中砷稳定效果的研究

Study on Effects of Composite Organic or Inorganic Agents on the Stabilization of Arsenic(As) in Soil

采用模拟砷污染土壤为研究对象,利用有机无机稳定药剂对污染土壤进行稳定化处理,通过单因素实验和复配实验,分析稳定后土壤砷的浸出毒性及形态变化。单因素实验结果表明:Fe S、Ca O及有机肥对砷的最佳稳定效率分别为73.54%、76.86%和39.56%,Fe S≈Ca O>有机肥;复配实验结果表明:在总投加量为2%,Fe S、Ca O质量比为1∶3的Fe S+Ca O复配基础上,分别投加质量比为2%、4%、6%、8%、10%的有机肥,对砷的稳定效果分别达到95.09%、96.11%、96.40%、97.55%、97.37%。形态分析表明砷的稳定处理主要将土壤中的砷从可交换态转化为难移动态的Fe-As结合态、Ca-As结合态,Al-As结合态和残渣态变化不大。

To immobilize arsenic in the contaminated soil, several organic and inorganic materials had been applied in the stabilization treatment through single factor experiment and compound experiments. The leaching toxicity test and morphological analysis were carried out to evaluate the efficiency of the materials after stabilization treatment. The results of single factor experiments showed that the stable efficiency of Fe S, Ca O and organic fertilizers on arsenic ordered as 73.54%, 76.86% and 39.56%. In the compound experiment, under the situations of the total dosage of the composite materials equaling to 2%, as well as Fe S and Ca O being mixed at mass ratio of 1:3, the arsenic stable efficiency could reach up to 95.09%, 96.11%, 96.40%, 97.55%, 97.37% with the extra additions of organic fertilizers of 2%, 4%, 6%, 8%, 10%, respectively. The morphological analysis indicated that the stabilization treatments mainly changed the arsenic exchangeable states by transforming the exchangeable As into immobilized Fe-As and Ca-As status, while Al-As status and residual status changed little.