Institute of Agricultural Resources and Environment, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, China; Key Laboratory of Agro-Environment in Downstream of Yangze Plain, Ministry of Agriculture and Rural Affairs of the People's Republic of China, Nanjing, 210014, Jiangsu, China.
Institute of Agricultural Resources and Environment, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, China; Key Laboratory of Agro-Environment in Downstream of Yangze Plain, Ministry of Agriculture and Rural Affairs of the People's Republic of China, Nanjing, 210014, Jiangsu, China; School of Agriculture and Environment, The University of Western Australia, Perth, WA 6009, Australia.
Chemosphere. 2021 Jan;263:128085. doi: 10.1016/j.chemosphere.2020.128085. Epub 2020 Aug 26.
Soil contaminated by combinations of heavy metals and organic pollutants has become an increasingly prominent environmental issue. Developing efficient technologies to synchronously decontaminate such co-contaminated sites is challenging and imperative. In our previous study for the treatment of Copper (Cu) and pyrene contaminated soil, electrokinetics (EK) coupled acidic permanganate (PM) performed best for degradation of pyrene near the injection spot, but it unfortunately prevented the migration of Cu. In order to further enhance the removal efficiency of these contaminants, in this study, batch experiments were conducted to investigate the feasibility of delivering PM by EK under regular refreshment of acidoxidant along with amplification of voltage gradient. The results showed that PM can be transported from cathode to anode to S2 section (near the anode) with a slow mass transfer rate via electromigration and reversed electroosmotic flow, and further delivery was achieved when Cu and pyrene were coexisted. The reaction of pyrene with PM produced a lower soil pH condition, which was conductive to the transport of Cu, and the existence of Cu promoted the migration of PM. The coexistence of Cu and pyrene favored the removal efficiency of the pollutants, and 92.8% of Cu and 70.7% of pyrene were removed after 15 d EK treatment. Thus, EK + acidic PM with regularly supplement of oxidant is appropriate to achieve complete mass depletion of heavy metals and PAHs, especially in low buffered soils.
受重金属和有机污染物组合污染的土壤已成为一个日益突出的环境问题。开发高效的技术来同步治理这种复合污染场地具有挑战性和必要性。在我们之前关于处理铜 (Cu) 和芘污染土壤的研究中，电化学（EK）结合酸性高锰酸盐（PM）在注入点附近对芘的降解效果最好，但不幸的是，它阻止了 Cu 的迁移。为了进一步提高这些污染物的去除效率，本研究通过EK 输送 PM 进行了批量实验，以研究在酸氧化剂定期更新以及电压梯度放大的情况下通过 EK 输送 PM 的可行性。结果表明，PM 可以通过电迁移和反向电渗流从阴极缓慢迁移到阳极和 S2 区（靠近阳极），并且当 Cu 和芘共存时可以进一步输送。PM 与芘反应产生的较低土壤 pH 条件有利于 Cu 的迁移，而 Cu 的存在则促进了 PM 的迁移。Cu 和芘的共存有利于污染物的去除效率，经过 15 d EK 处理后，Cu 的去除率为 92.8%，芘的去除率为 70.7%。因此，EK+定期补充氧化剂的酸性 PM 适合实现重金属和 PAHs 的完全耗尽，特别是在低缓冲土壤中。
