Soil Ecology Lab, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, PR China; Key Laboratory of Soil Environmental and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, PR China.
State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, PR China.
J Hazard Mater. 2014 Jan 15;264:505-13. doi: 10.1016/j.jhazmat.2013.10.032. Epub 2013 Oct 25.
The effectiveness of anaerobic bioremediation systems for PAH-contaminated soil may be constrained by low contaminants bioaccessibility due to limited aqueous solubility and lack of suitable electron acceptors. Information on what is the rate-limiting factor in bioremediation process is of vital importance in the decision in what measures can be taken to assist the biodegradation efficacy. In the present study, four different microcosms were set to study the effect of methyl-β-cyclodextrin (MCD) and nitrate addition (N) on PAHs biodegradation under anaerobic conditions in a red paddy soil. Meanwhile, sequential Tenax extraction combined with a first-three-compartment model was employed to evaluate the rate-limiting factors in MCD enhanced anaerobic biodegradation of PAHs. Microcosms with both 1% (w/w) MCD and 20mM N addition produced maximum biodegradation of total PAHs of up to 61.7%. It appears rate-limiting factors vary with microcosms: low activity of degrading microorganisms is the vital rate-limiting factor for control and MCD addition treatments (CK and M treatments); and lack of bioaccessible PAHs is the main rate-limiting factor for nitrate addition treatments (N and MN treatments). These results have practical implications for site risk assessment and cleanup strategies.
受污染物水溶度低和缺乏合适电子受体的限制，厌氧生物修复系统对多环芳烃污染土壤的修复效果可能会受到限制。了解生物修复过程中的限速因素对于决定可以采取哪些措施来提高生物降解效率至关重要。本研究设置了四个不同的微宇宙，研究在红壤中，在厌氧条件下，添加甲基-β-环糊精（MCD）和硝酸盐（N）对多环芳烃生物降解的影响。同时，采用顺序 Tenax 提取结合三分区模型，评估 MCD 增强多环芳烃厌氧生物降解过程中的限速因素。添加 1%（w/w）MCD 和 20mM N 的微宇宙中，多环芳烃的总生物降解率最高可达 61.7%。似乎限速因素随微宇宙而变化：对于对照和 MCD 添加处理（CK 和 M 处理），降解微生物活性低是关键的限速因素；对于硝酸盐添加处理（N 和 MN 处理），生物可利用的多环芳烃缺乏是主要的限速因素。这些结果对现场风险评估和清理策略具有实际意义。
