Department of Agricultural Resources and Environment, Nanjing University of Information Science and Technology, Nanjing, 210044, China.
Jiangsu Key Laboratory of Agricultural Meteorology, Nanjing University of Information Science & Technology, Nanjing, 210044, China.
Environ Sci Pollut Res Int. 2018 Jun;25(18):17499-17508. doi: 10.1007/s11356-018-1929-y. Epub 2018 Apr 16.
Stabilization technology is one of widely used remediation technologies for cadmium (Cd)-contaminated agricultural soils, but stabilized Cd in soil may be activated again when external conditions such as acid rain occurred. Therefore, it is necessary to study the effect of acid rain on the performance of different stabilizing agents on Cd-polluted agriculture soils. In this study, Cd-contaminated soils were treated with mono-calcium phosphate (MCP), mono-ammonium phosphate (MAP), and artificial zeolite (AZ) respectively and incubated 3 months. These treatments were followed by two types of simulated acid rain (sulfuric acid rain and mixed acid rain) with three levels of acidity (pH = 3.0, 4.0, and 5.6). The chemical forms of Cd in the soils were determined by Tessier's sequential extraction procedure, and the leaching toxicities of Cd in the soils were assessed by toxicity characteristic leaching procedure (TCLP). The results show that the three stabilizing agents could decrease the mobility of Cd in soil to some degree with or without simulated acid rain (SAR) treatment. The stabilization performances followed the order of AZ < MAP < MCP. Acid rain soaking promoted the activation of Cd in stabilized soil, and both anion composition and pH of acid rain were two important factors that influenced the stabilization effect of Cd.
稳定化技术是一种广泛应用于修复镉（Cd）污染农田土壤的技术，但当发生酸雨等外部条件时，土壤中稳定的 Cd 可能会再次被激活。因此，有必要研究酸雨对不同稳定剂在 Cd 污染农田土壤上性能的影响。本研究采用磷酸一钙（MCP）、磷酸一铵（MAP）和人造沸石（AZ）分别处理 Cd 污染土壤，并进行了 3 个月的孵化。随后，用两种类型的模拟酸雨（硫酸雨和混合酸雨）进行处理，酸度分为 3 个水平（pH = 3.0、4.0 和 5.6）。采用 Tessier 连续提取程序测定土壤中 Cd 的化学形态，采用毒性特征浸出程序（TCLP）评估土壤中 Cd 的浸出毒性。结果表明，三种稳定剂在有无模拟酸雨（SAR）处理的情况下，都能在一定程度上降低土壤中 Cd 的迁移性。稳定化性能的顺序为 AZ < MAP < MCP。酸雨浸泡促进了稳定化土壤中 Cd 的活化，酸雨的阴离子组成和 pH 是影响 Cd 稳定化效果的两个重要因素。
