Mechanisms of attenuation of metal availability in in situ remediation treatments
Mechanisms of attenuation of metal availability in in situ remediation treatments
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DOI：
10.1021/es025558g
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发表时间：
2002-09-15
影响因子：
11.4
通讯作者：
Cozens, G
中科院分区：
文献类型：
--
作者：
Hamon, RE;McLaughlin, MJ;Cozens, G
一套原位修复金属污染土壤的技术包括添加活性材料，降低金属的可用性。到目前为止，很难评估修正引起的金属可用性下降是否仅仅是由于金属吸附增加，还是由于表面沉淀或其他固定机制。这使得很难预测这种补救治疗的长期稳定性。采用同位素稀释技术，再加上逐步酸化处理，我们研究了不稳定池中的镉和锌污染的土壤修改与CaCO3，KH2PO4，赤泥，或高岭土副产品的变化。KH_2PO_4处理土壤对Cd和Zn的固定作用最大。在这种处理中的固定模式也被发现是耐土壤酸化。结果允许明确区分三类衰减机制，假设它们对环境变化的弹性增加，如下：可逆吸附<恒定pH下的不可逆“固定”<在一定pH范围内的不可逆“固定”。
One suite of in situ technologies for remediating metal contaminated soils involves the addition of reactive materials which lower metal availability. Until now it has been difficult to assess whether the amendment induced decrease in metal availability is due simply to increased sorption of the metal or whether it is the result of surface precipitation,or other-fixation mechanisms. This has made it difficult to predict the long-term stability of such remedial treatments. Using an isotopic dilution technique coupled with a stepwise acidification treatment, we examined changes in the labile pool of Cd and Zn in a polluted soil amended with either CaCO3, KH2PO4, redmud, or a kaolin byproduct. Fixation cif both Cd and Zn Was greatest in the KH2PO4 treated soil. The mode of fixation in this treatment was also found to be resistant to soil acidification. The results allowed a clear distinction between three classes of attenuation mechanisms which are hypothesized to increase in their resilience,to environmental change as follows: reversible sorption < irreversible "fixation" at constant pH < irreversible "fixation" across a range of pH.