Liao Xiaoyong, Li You, Yan Xiulan
Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Science, Beijing 100101, China.
Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Science, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China.
J Environ Sci (China). 2016 Mar;41:202-210. doi: 10.1016/j.jes.2015.06.017. Epub 2015 Sep 28.
Batch experiments were conducted with a heavy metals and arsenic co-contaminated soil from an abandoned mine to evaluate the feasibility of a remediation technology that combines sieving with soil washing. Leaching of the arsenic and heavy metals from the different particle size fractions was found to decrease in the order: <0.1, 2-0.1, and >2mm. With increased contact time, the concentration of heavy metals in the leachate was significantly decreased for small particles, probably because of adsorption by the clay soil component. For the different particle sizes, the removal efficiencies for Pb and Cd were 75%-87%, and 61%-77% for Zn and Cu, although the extent of removal was decreased for As and Cr at <45%. The highest efficiency by washing for Pb, Cd, Zn, and As was from the soil particles >2mm, although good metal removal efficiencies were also achieved in the small particle size fractions. Through SEM-EDS observations and correlation analysis, the leaching regularity of the heavy metals and arsenic was found to be closely related to Fe, Mn, and Ca contents of the soil fractions. The remediation of heavy metal-contaminated soil by sieving combined with soil washing was proven to be efficient, and practical remediation parameters were also recommended.
采用某废弃矿山的重金属和砷共污染土壤进行了批次实验，以评估筛分与土壤冲洗相结合的修复技术的可行性。结果发现，不同粒径级分中砷和重金属的浸出量按以下顺序降低：<0.1mm、2-0.1mm和>2mm。随着接触时间的增加，小颗粒渗滤液中重金属的浓度显著降低，这可能是由于黏土成分的吸附作用。对于不同粒径，铅和镉的去除效率为75%-87%，锌和铜为61%-77%，而砷和铬的去除程度则低于45%。通过冲洗，>2mm土壤颗粒中铅、镉、锌和砷的去除效率最高，不过小粒径级分中的金属去除效率也较好。通过扫描电子显微镜-能谱（SEM-EDS）观察和相关性分析，发现重金属和砷的浸出规律与土壤组分中的铁、锰和钙含量密切相关。事实证明，筛分与土壤冲洗相结合修复重金属污染土壤是有效的，并推荐了实际的修复参数。
