School of Environment, Tsinghua University, Beijing, 100084, China.
Key Laboratory for Solid Waste Management and Environment Safety, Ministry of Education of China, Beijing, 100084, China.
Sci Rep. 2017 Sep 11;7(1):11177. doi: 10.1038/s41598-017-11682-3.
Soil washing is an effective remediation method to remove heavy metals from contaminated soil. However, it produces wastewater that contains large amounts of heavy metals, which lead to serious pollution. This study investigated the removal of vanadium (V) from synthetic soil washing effluent using BOF steel slag. The effects of particle size, slag dosage, initial pH, and initial vanadium concentration on removal behavior were studied. Adsorption kinetics and isotherms were also analyzed. The results showed that the vanadium removal efficiency increased as the steel slag particle size decreased and as the amount of slag increased. The initial pH and vanadium concentration did not play key roles. At the optimum particle size (<0.15 mm) and dosage (50 g/L), the removal rate reached 97.1% when treating 100 mg/L of vanadium. The influence of the washing reagent residue was studied to simulate real conditions. Citric acid, tartaric acid, and NaEDTA all decreased the removal rate. While oxalic acid did not have negative effects on vanadium removal at concentrations of 0.05-0.2 mol/L, which was proved by experiments using real washing effluents. Considering both soil washing effect and effluent treatment, oxalic acid of 0.2 mol/L is recommended as soil washing reagent.
土壤洗脱是一种从污染土壤中去除重金属的有效修复方法。然而，它会产生含有大量重金属的废水，从而导致严重的污染。本研究采用转炉钢渣去除人工合成土壤洗脱废水中的钒（V）。考察了粒径、钢渣用量、初始 pH 值和初始钒浓度对去除行为的影响。还分析了吸附动力学和等温线。结果表明，随着钢渣粒径的减小和用量的增加，钒的去除效率增加。初始 pH 值和钒浓度没有起到关键作用。在最佳粒径（<0.15mm）和用量（50g/L）下，处理 100mg/L 钒时，去除率达到 97.1%。研究了洗涤试剂残留的影响，以模拟实际情况。柠檬酸、酒石酸和 NaEDTA 均降低了去除率。而草酸在 0.05-0.2mol/L 浓度下对钒去除没有负面影响，这通过使用实际洗脱废水的实验得到了证明。考虑到土壤洗脱效果和废水处理，建议将 0.2mol/L 的草酸作为土壤洗脱试剂。
