非饱和土壤中汽油组分的微生物厌氧降解研究

发布时间：2018-08-29 20:18

【摘要】：埋地油罐油品泄漏问题日趋突出，已成为一个重要的环境问题。非饱和带既是泄漏油品进入地下水/大气的通道，也是地下水/大气免受泄漏油品污染的一道屏障。因此，研究非饱和带土壤中汽油的微生物降解机制，可为埋地油罐场地地下水/大气保护提供科学依据。本研究以汽油为目标污染物，以非饱和的深层土壤为研究对象，开展了（1）典型汽油泄漏场地土壤中微生物丰度及群落多样性；（2）电子受体硝酸盐对非饱和土壤中汽油组分厌氧微生物降解的影响；（3）电子受体硫酸盐对非饱和土壤中汽油组分厌氧微生物降解的影响研究。实时定量PCR结果表明，未污染的对照地和汽油泄漏场地中表层土壤中微生物丰度高于深层土壤中的微生物丰度（1-2个数量级）。基于克隆文库的RDP分析结果表明，汽油泄漏地土壤细菌群落多样性明显低于对照场地土壤，且表层土壤细菌群落多样性明显高于深层土壤。受汽油污染的深层土壤AS和BS测序序列分别为97和95个，主要为Betaproteobacteria，而未受污染的对照场地深层土壤CKS共测序99个克隆，测得的序列可归入7个细菌类群（门）。 180天厌氧培养后，未添加硝酸盐的对照处理（SGN0）土壤中单环芳烃浓度未发生明显变化，但TPH（C6-C9）和TPH（C10-C12）降解率较高，分别为33%和37%。添加硝酸盐电子受体的处理（SGN40、SGN200和SGN1000）土壤中甲苯、乙苯、TPH（C6-C9）和TPH（C10-C12）降解较为明显，降解率分别为10%-47%、22%-82%、42%-57%和39%-52%，，且硝酸盐添加量越多，其降解率越高。尽管如此，其他单环芳烃的降解不明显。相对于对照处理，180天厌氧培养后添加硫酸盐电子受体处理（SGS40、SGS200和SGS1000）土壤中单环芳烃如甲苯、乙苯、二甲苯、1,2,4-三甲苯、仲丁苯以及TPH (C6-C9)、TPH (C10-C12)等含量未发生明显变化。
[Abstract]:The leakage of buried oil tank has become an important environmental problem. Unsaturated zone is not only the passage of leaking oil into groundwater / atmosphere, but also the barrier of groundwater / atmosphere from leaking oil. Therefore, the study of microbial degradation mechanism of gasoline in unsaturated zone soil can provide scientific basis for groundwater / atmospheric protection of buried oil tank site. Taking gasoline as the target pollutant and unsaturated deep soil as the research object, this study carried out (1) microbial abundance and community diversity in the soil of typical gasoline leak site; (2) the effect of electron receptor nitrate on anaerobic microbial degradation of gasoline component in unsaturated soil and (3) the effect of electron receptor sulfate on anaerobic microbial degradation of gasoline component in unsaturated soil. The results of real-time quantitative PCR showed that the microbial abundance in the surface soil of the unpolluted control area and the gasoline spill site was higher than that in the deep soil (1-2 orders of magnitude). The results of RDP analysis based on clone library showed that the diversity of soil bacterial community in gasoline spill site was significantly lower than that in control soil, and the diversity of bacterial community in surface soil was significantly higher than that in deep soil. The sequence of AS and BS in the deep soil contaminated by gasoline were 97 and 95, respectively. The CKS sequence of the deep soil in the uncontaminated control site was 99 clones, and the sequence of CKS in the deep soil was 97 and 95, respectively. After 180 days of anaerobic culture, the concentration of monocyclic aromatic hydrocarbons in soil of control (SGN0) treatment without nitrate had no significant change, but the degradation rates of TPH (C6-C9) and TPH (C10-C12) were higher (33% and 37%, respectively). The degradation of toluene (C6-C9) and TPH (C10-C12) in soil treated with nitrate electron receptor (SGN40,SGN200 and SGN1000) was obvious, and the degradation rate was 10-47 and 22-822% and 39-52%, respectively, and the higher the nitrate content was, the higher the degradation rate was. However, the degradation of other monocyclic aromatic hydrocarbons is not obvious. The contents of monocyclic aromatic hydrocarbons (such as toluene, ethylbenzene, dimethylbenzene), secondary butadiene and TPH (C6-C9) TPH (C10-C12) in soil treated with sulphate electron receptor (SGS40,SGS200 and SGS1000) were not significantly changed compared with those of control treatment after 180 days anaerobic culture.
【学位授予单位】：轻工业环境保护研究所
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：X55;X172

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