College of Environmental Sciences, Sichuan Agricultural University, Wenjiang, 611130, PR China.
College of Environmental Sciences, Sichuan Agricultural University, Wenjiang, 611130, PR China.
J Hazard Mater. 2019 Mar 15;366:177-183. doi: 10.1016/j.jhazmat.2018.11.109. Epub 2018 Dec 1.
Soil washing, which is used to remove heavy metals from soil, is dependent on suitable washing agents. However, there is still a lack of economical, environmentally friendly washing agents with high removal efficiency. In this study, three washing agents, carboxyalkylthiosuccinic acid (CETSA), copolymer of maleic and acrylic acid (MA/AA) and ethylenediamine tetra acetic acid (EDTA), were used to remove heavy metals from contaminated soil. The influence of washing solution concentration, pH and washing time on heavy metals removal was also investigated. The cadmium (Cd), lead (Pb), and zinc (Zn) removal efficiencies increased as washing solution concentrations increased from 0 to 60 g L, while they declined as pH increased from 3 to 8. Despite fluctuations between 90 and 120 min, heavy metal removal efficiencies increased continuously from 10 to 90 min. The three agents also effectively reduced the potential risks of Cd, Pb, and Zn in contaminated soil, but only CETSA and MA/AA produced no significant changes in chemical properties. Fourier transform infrared spectroscopy revealed that the hydroxyl, carboxyl, carbonyl, methoxyl, and sulfur groups were related to the heavy metal ions from the soil colloids. Thus, CETSA and MA/AA were suitable washing agents for remediation of heavy metals contaminated soil.
土壤淋洗是一种用于去除土壤中重金属的方法，其依赖于合适的淋洗剂。然而，目前仍然缺乏经济、环保且具有高去除效率的淋洗剂。本研究选用羧基烷基硫代琥珀酸（CETSA）、马来酸和丙烯酸共聚物（MA/AA）和乙二胺四乙酸（EDTA）三种淋洗剂，用于去除污染土壤中的重金属。还研究了淋洗液浓度、pH 值和淋洗时间对重金属去除的影响。当淋洗液浓度从 0 增加到 60 g/L 时，镉（Cd）、铅（Pb）和锌（Zn）的去除效率增加，而当 pH 值从 3 增加到 8 时，去除效率降低。尽管在 90 至 120 分钟之间存在波动，但重金属的去除效率从 10 分钟开始连续增加到 90 分钟。这三种试剂还可以有效降低污染土壤中 Cd、Pb 和 Zn 的潜在风险，但只有 CETSA 和 MA/AA 对化学性质没有显著影响。傅里叶变换红外光谱表明，土壤胶体中的重金属离子与羟基、羧基、羰基、甲氧基和硫基有关。因此，CETSA 和 MA/AA 是修复重金属污染土壤的合适淋洗剂。
