Jiangsu Province Engineering Research Center of Soil and Groundwater Pollution Prevention and Control, Jiangsu Provincial Key Laboratory of Environmental Engineering, Jiangsu Provincial Academy of Environmental Science, Nanjing, 210036, China; Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China; State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing, 210023, China.
School of Civil Engineering, University of Leeds, Leeds, LS2 9JT, UK.
Environ Pollut. 2024 Jun 15;351:124042. doi: 10.1016/j.envpol.2024.124042. Epub 2024 Apr 26.
Chlorinated hydrocarbons (CHs) pose significant health risks due to their suspected carcinogenicity, necessitating urgent remediation efforts. While the combination of zero-valent iron (Fe) and microbial action shows promise in mitigating CH contamination, field studies on this approach are scarce. We devised a novel three-layer permeable reactive barrier (PRB) material incorporating Fe and coconut shell biochar, effectively implemented at a typical CH-contaminated site. Field monitoring data revealed conducive conditions for reductive dechlorination of CHs, characterized by low oxygen levels and a relatively neutral pH in the groundwater. The engineered PRB material consistently released organic carbon and iron, fostering the proliferation of CH-dechlorinating bacteria. Over a 250-day operational period, the pilot-scale PRB demonstrated remarkable efficacy in CH removal, achieving removal efficiencies ranging from 21.9% to 99.6% for various CH compounds. Initially, CHs were predominantly eliminated through adsorption and iron-mediated reductive dechlorination. However, microbial reductive dechlorination emerged as the predominant mechanism for sustained and long-term CHs removal. These findings underscore the economic viability and effectiveness of our approach in treating CH-contaminated groundwater, offering promising prospects for broader application in environmental remediation efforts.
氯化烃（CHs）因其疑似致癌性而对健康构成重大威胁，因此需要紧急进行修复。虽然零价铁（Fe）和微生物作用的结合在减轻 CH 污染方面显示出了一定的潜力，但针对这种方法的野外研究却很少。我们设计了一种新型的三层渗透反应屏障（PRB）材料，其中包含 Fe 和椰子壳生物炭，成功地应用于一个典型的 CH 污染场地。野外监测数据显示，地下水的低氧水平和相对中性的 pH 值有利于 CH 的还原脱氯。工程化的 PRB 材料持续释放有机碳和铁，促进了 CH 脱氯菌的增殖。在 250 天的运行期间，中试规模的 PRB 在 CH 去除方面表现出了显著的效果，对各种 CH 化合物的去除效率范围为 21.9%至 99.6%。最初，CHs 主要通过吸附和铁介导的还原脱氯去除。然而，微生物还原脱氯成为持续和长期去除 CHs 的主要机制。这些发现强调了我们的方法在处理 CH 污染地下水方面的经济可行性和有效性，为更广泛地应用于环境修复努力提供了有希望的前景。
