School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology (GIST), 123 Cheomdangwagi-ro, Buk-gu, Gwangju, 61005, Republic of Korea.
Department of Energy and Resources Engineering, Chonnam National University, Gwangju, 61186, Republic of Korea.
Environ Geochem Health. 2019 Feb;41(1):447-460. doi: 10.1007/s10653-018-0173-1. Epub 2018 Aug 21.
Soil stabilization is a remedial technique that reduces the exposure of the soil environment to soil contaminants. Its efficacy can be assessed by determining whether the environmental availability of a contaminant decreases following treatment. We evaluated several chemical leaching treatments by assessing both contaminant leachability and bioaccumulation in the earthworm Eisenia fetida, and determined the most effective treatment for achieving soil stabilization. Soil samples contaminated with As, Cd, Cu, Pb, and/or Zn were collected from abandoned mine areas and stabilized by adding limestone and steel slag (5% and 2% w/w, respectively). All leaching and earthworm tests were conducted using both contaminated and stabilized soils. In addition to bioaccumulation in earthworms, several toxicity parameters (number of cocoons, growth changes, and survival rates) were also assessed to determine the effects of the treatments on the earthworms. The study showed that treatment of soil with EDTA-NHOAc resulted in a significant decrease in contaminant leachability following soil stabilization. There was an increase in survival and growth of earthworms exposed to the stabilized soil compared with those exposed to the non-stabilized soil. Bioaccumulation in earthworms was found to be statistically correlated with the leachability of As by EDTA-NHOAc. We conclude that limestone and steel slag effectively decreased the availability of heavy metals in the soil and reduced the toxicity to earthworms. Leaching with EDTA-NHOAc has the potential to be predictive in estimating the bioavailability of As in soils, but further studies are needed if it is to be proposed as a standard method.
土壤稳定化是一种修复技术，可减少土壤环境中土壤污染物的暴露。可以通过确定处理后污染物的环境可利用性是否降低来评估其功效。我们通过评估蚯蚓（Eisenia fetida）的污染物浸出率和生物累积性，评估了几种化学浸出处理方法，并确定了实现土壤稳定化的最有效处理方法。从废弃矿区采集了受 As、Cd、Cu、Pb 和/或 Zn 污染的土壤样本，并通过添加石灰石和钢渣（分别为 5%和 2%w/w）对其进行稳定化处理。所有浸出和蚯蚓试验均使用污染土壤和稳定化土壤进行。除了蚯蚓的生物累积性外，还评估了几个毒性参数（茧数、生长变化和存活率），以确定处理方法对蚯蚓的影响。研究表明，土壤经 EDTA-NHOAc 处理后，土壤稳定化可显著降低污染物的浸出率。与暴露于非稳定化土壤的蚯蚓相比，暴露于稳定化土壤的蚯蚓的存活率和生长率均有所提高。蚯蚓的生物累积性与 EDTA-NHOAc 浸出的 As 可浸出性呈统计学相关。我们得出结论，石灰石和钢渣可有效降低土壤中重金属的有效性，并降低对蚯蚓的毒性。EDTA-NHOAc 浸出具有预测土壤中 As 生物可利用性的潜力，但如果要将其提议为标准方法，则需要进一步研究。
