The use of chelating agents in soil washing has been known to be an efficient, eco–friendly, and inexpensive treatment process for the removal of heavy metal contamination. In this study, statistically designed lab-scale soil washing experiments were carried out using two chelating agents i.e., ethylene diamine tetraacetic acid (EDTA) and N-acetyl-L-cysteine (NAC). The effects of pH, contact time and dosage of wash solution on chromium (Cr⁺⁶) removal efficiency (RE) was investigated and optimized using response surface methodology (RSM). The ANOVA analysis of the experimental design for both the chelating agents revealed that pH is the key influencing parameter in Cr⁺⁶ removal. The optimum conditions were found to be: pH - 5.5, contact time - 216 h, dosage of EDTA - 4128 mg/kg and dosage of NAC - 300 mg/kg. The projected Cr⁺⁶ RE under these optimum conditions was 14.3% and 65.7%, for EDTA and NAC, respectively. The results from this investigation indicated that soil washing with NAC could be a better alternative to EDTA for Cr⁺⁶ removal from soil.

众所周知，在土壤洗涤中使用螯合剂是一种去除重金属污染的有效、环保和廉价的处理工艺。在这项研究中，使用两种螯合剂，即乙二胺四乙酸 (EDTA) 和N-乙酰基-L-半胱氨酸 (NAC)，进行了统计设计的实验室规模土壤洗涤实验。使用响应面法 (RSM) 研究和优化了 pH 值、接触时间和洗涤溶液用量对铬 (Cr ^{+6 ) 去除效率 (RE) 的影响。}两种螯合剂实验设计的 ANOVA 分析表明，pH 是 Cr ^{+6中的关键影响参数}移动。最佳条件为：pH - 5.5，接触时间 - 216 h，EDTA 用量 - 4128 mg/kg 和 NAC 用量 - 300 mg/kg。对于 EDTA 和 NAC，在这些最佳条件下预计的 Cr ⁺⁶ RE 分别为 14.3% 和 65.7%。这项调查的结果表明，用 NAC 清洗土壤可能是 EDTA从土壤中去除Cr ^{+6的更好替代方案。}