纳米零价铁与黑曲霉发酵液联用对砷锑污染土壤的淋洗修复

土壤砷 (As) 、锑 (Sb) 污染对生态环境和人体健康有着潜在的风险，采用黑曲霉发酵液 (FB) 与纳米零价铁 (nZVI) 联用淋洗修复As、Sb污染土壤。通过振荡淋洗实验，探究nZVI强化FB淋洗去除As、Sb的效果及不同条件下对As、Sb淋洗效率的影响。结果表明，制备的FB对污染土壤中As和Sb有着较好的去除效果，去除率可达84.1%和71.8%；nZVI对FB去除As、Sb有强化作用，在nZVI质量浓度为0.1 g·L⁻¹、pH为1和淋洗时间为60 min的条件下，其淋洗效果最佳，对As、Sb淋洗效率可达96.6%和95.6%，修复后的土壤达到《土壤环境质量 建设用地土壤污染风险管控标准 (试行) 》 (GB 36600-2018) 二类用地标准。nZVI-FB对土壤中As、Sb的解吸动力学符合拟二级动力学方程。nZVI-FB能够有效的提取土壤中As、Sb的铁铝氧化物结合态。本研究结果可为As、Sb复合污染土壤的淋洗修复提供参考。

Washing remediation of arsenic and antimony contaminated soil by the combination of nano-zero-valent iron and Aspergillus niger fermentation broth

Arsenic (As) and antimony (Sb) contamination in soils pose potential risks to the ecological environment and human health. Remediation of As and Sb contaminated soil by washing with the combination of Aspergillus niger fermentation broth (FB) and nano zero-valent iron (nZVI). The enhancement effect of nZVI combined with the broth in the soil washing process was studied, and the impacts of different conditions (such as pH, time, etc.) on the As and Sb washing efficiency were also investigated. The results showed that Aspergillus niger fermentation broth demonstrated good washing efficiencies on As and Sb in the contaminated soil, reaching 84.1% and 71.8%, respectively. The best elution effect was achieved at the nZVI addition of 0.1 g·L−1, pH 1 and 60 min of washing time, with the removal efficiency of 96.6% and 95.6% for As and Sb, and the As and Sb concentrations that remained in soil were lower than the standard value in Soil Environmental Quality, Risk Control Standard for Soil Contamination of Development Land in China. The kinetics of desorption of As and Sb from soil by nZVI-FB is consistent with the proposed secondary kinetic equation. The mixed washing agent can effectively extract the Fe/Al oxide bound state of As and Sb from the soil. The results of this study can provide a reference for the remediation of leaching of As and Sb contaminated soil.