Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China.
Environ Sci Pollut Res Int. 2013 Feb;20(2):976-86. doi: 10.1007/s11356-012-1064-0. Epub 2012 Jul 17.
Polycyclic aromatic hydrocarbon (PAH) and metal-polluted sites caused by abandoned coking plants are receiving wide attention. To address the associated environmental concerns, innovative remediation technologies are urgently needed. This study was initiated to investigate the feasibility of a cleanup strategy that employed an initial phase, using methyl-β-cyclodextrin (MCD) solution to enhance ex situ soil washing for extracting PAHs and metals simultaneously, followed by the addition of PAH-degrading bacteria (Paracoccus sp. strain HPD-2) and supplemental nutrients to treat the residual soil-bound PAHs. Elevated temperature (50 °C) in combination with ultrasonication (35 kHz, 30 min) at 100 g MCD L(-1) was effective in extracting PAHs and metals to assist soil washing; 93 % of total PAHs, 72 % of Cd, 78 % of Ni, 93 % of Zn, 84 % of Cr, and 68 % of Pb were removed from soil after three successive washing cycles. Treating the residual soil-bound PAHs for 20 weeks led to maximum biodegradation rates of 34, 45, 36, and 32 % of the remaining total PAHs, 3-ring PAHs, 4-ring PAHs, and 5(+6)-ring PAHs after washing procedure, respectively. Based on BIOLOG Ecoplate assay, the combined treatment at least partially restored microbiological functions in the contaminated soil. The ex situ cleanup strategy through MCD-enhanced soil washing followed by microbial augmentation can be effective in remediating PAH and metal-contaminated soil.
多环芳烃（PAH）和废弃炼焦厂造成的金属污染场地受到广泛关注。为了解决相关的环境问题，迫切需要创新的修复技术。本研究旨在探讨一种清理策略的可行性，该策略采用初始阶段，使用甲基-β-环糊精（MCD）溶液增强异位土壤洗涤，同时提取 PAH 和金属，然后添加 PAH 降解菌（假单胞菌属 HPD-2 株）和补充营养物质来处理残留的土壤结合态 PAH。在 100 g MCD L(-1) 下，升高温度（50°C）并结合超声（35 kHz，30 min）可有效提取 PAH 和金属，以辅助土壤洗涤；经过三次连续洗涤循环后，土壤中 93%的总 PAH、72%的 Cd、78%的 Ni、93%的 Zn、84%的 Cr 和 68%的 Pb 被去除。处理残留的土壤结合态 PAH 20 周后，在洗涤程序后，剩余总 PAH 的生物降解率分别达到 34%、45%、36%和 32%，3 环 PAH、4 环 PAH 和 5(+6)-环 PAH。基于 BIOLOG Ecoplate 测定，联合处理至少部分恢复了污染土壤的微生物功能。通过 MCD 增强的土壤洗涤和微生物增强的异位清理策略可以有效地修复 PAH 和金属污染土壤。
