Liang Yuting, Nostrand Joy D Van, Wang Jian, Zhang Xu, Zhou Jizhong, Li Guanghe
Department of Environmental Science and Engineering, Tsinghua University, Beijing, China.
Chemosphere. 2009 Apr;75(2):193-9. doi: 10.1016/j.chemosphere.2008.12.007. Epub 2009 Jan 13.
Ozonation with a subsequent biodegradation treatment was performed to remove recalcitrant organic compounds from long-term weathered crude oil contaminated soil. Samples were analyzed by GC/MS and column chromatography to monitor changes in crude oil composition. A functional gene array was used to examine microbial community dynamics. After a 6h ozonation treatment with a constant concentration of 10mgO(3)L(-1) at a flow rate of 2.0Lmin(-1), an average removal of crude oil was 22%. The concentration of long-chain n-alkanes (C(19)-C(28)) decreased while more biodegradable short-chain alkanes (C(14)-C(16)), n-aldehydes (C(13)-C(20)), and n-monocarboxylic acids (C(9)-C(20)) appeared. In the subsequent direct biodegradation and bioaugmentation, an additional 12-20% of residuals were removed. The total microbial functional gene numbers and overall genetic diversity decreased after ozonation. Also, most of the key functional genes pertaining to carbon, nitrogen, and sulfur cycling and organic contaminant degradation decreased, ranging from 20% to below the detection limit. However, in the subsequent biodegradation treatments, with and without bioaugmentation, the abundance of key genes in most functional groups recovered. This study provided insight into changes in crude oil composition and microbial functional genes responses during ozonation and bioremediation treatments. These changes demonstrate the feasibility of an integrated ozonation and biodegradation treatment to remove recalcitrant soil contaminants.
采用臭氧化及后续生物降解处理方法，去除长期风化的原油污染土壤中的难降解有机化合物。通过气相色谱/质谱联用仪（GC/MS）和柱色谱法对样品进行分析，以监测原油成分的变化。使用功能基因阵列检测微生物群落动态。在以2.0L/min的流速、10mgO₃/L的恒定浓度进行6小时臭氧化处理后，原油的平均去除率为22%。长链正构烷烃（C₁₉ - C₂₈）的浓度降低，同时出现了更多可生物降解的短链烷烃（C₁₄ - C₁₆）、正醛（C₁₃ - C₂₀）和正单羧酸（C₉ - C₂₀）。在随后的直接生物降解和生物强化过程中，又去除了12% - 20%的残留污染物。臭氧化处理后，微生物功能基因总数和整体遗传多样性均有所下降。此外，大多数与碳、氮、硫循环及有机污染物降解相关的关键功能基因减少，降幅在20%至低于检测限之间。然而，在随后的生物降解处理中，无论是否进行生物强化，大多数功能组中的关键基因丰度都有所恢复。本研究深入了解了臭氧化和生物修复处理过程中原油成分及微生物功能基因的响应变化。这些变化证明了臭氧化与生物降解联合处理去除难降解土壤污染物的可行性。
