油污土壤修复过程中土壤酶活性及微生物群落结构变化

发布时间：2018-03-24 12:38

本文选题：石油污染土壤　切入点：生物修复　出处：《西安建筑科技大学》2017年硕士论文

【摘要】：石油是应用最为广泛的能源之一。在开采、运输和使用石油过程中不可避免存在着石油泄漏问题,对大气、水、土壤环境产生严重的影响并且危害人类健康。微生物修复技术由于其经济有效,不产生二次污染等特点,已成为国内外研究者最为关注的油污土壤修复方法。论文选取甘肃庆阳油田周边的陈旧性油污土壤为研究对象,利用生物强化联合生物刺激法对油污土壤进行了18周的实验室模拟修复。修复过程中沿程测定了不同组分石油烃含量、土壤不同形态氮素含量、土壤酶活性以及微生物群落结构的变化,并且对影响石油烃降解效果的环境因素和生物因素进行了相关分析。研究结果表明,石油污染土壤中的烷烃与多环芳烃含量分别为26000和5300mg/kg,属重度污染土壤。经过18周的生物修复,烷烃与多环芳烃含量分别降低到12800和2900 mg/kg,结果表明生物强化联合生物刺激可有效去除重度石油污染土壤中的烷烃和多环芳烃。修复18周,土壤总氮含量从初始的1830 mg/kg变为1600 mg/kg,其含量变化不大,氨态氮含量由初始的35.62 mg/kg降低至1.22mg/kg;硝态氮含量从45.43 mg/kg降低至7.17 mg/kg,且沿程呈持续降低趋势。土壤酶活的测定结果表明,土壤脱氢酶和多酚氧化酶活性均呈先升高后降低趋势;而土壤过氧化氢酶及脂肪酶活性在修复前期显著增大,修复后期保持稳定。SPSS相关分析结果表明,修复过程中石油烃的去除效率与土壤不同形态氮素含量、土壤四种酶活性之间具有显著相关性。利用高通量测序技术对修复后期不同处理中土壤微生物群落结构的变化进行分析,结果表明放线菌门(Actinobacteria)、变形菌门(Proteobacteria)、拟杆菌门(Bacteroidetes)、厚壁菌门(Firmicutes)等为该油污土壤中的优势菌门。微生物修复法对土壤中优势菌门及优势菌属所占丰度影响较大,经过18周的微生物修复,在属水平上原小单孢菌属(Promicromonospora)、假单胞菌(Pseudomonas)、分支杆菌(Mycobacterium)、交替赤细菌(Altererythrobacter)、未命名菌(Alkanibacter)等菌种丰度显著提高。
[Abstract]:Oil is one of the most widely used energy sources. In the process of exploitation, transportation and use of oil, there are inevitable problems of oil leakage, to the atmosphere, to water, The soil environment has serious effects and endangers human health. Because of its economic efficiency and no secondary pollution, microbial remediation technology, In this paper, the old oily soil around Qingyang Oilfield in Gansu Province is chosen as the research object. The oil contaminated soil was repaired by bioremediation combined with biological stimulation for 18 weeks. The contents of different components of petroleum hydrocarbons and different forms of nitrogen in soil were measured along the course of restoration. The changes of soil enzyme activity and microbial community structure were analyzed, and the environmental and biological factors affecting the degradation of petroleum hydrocarbons were analyzed. The alkanes and polycyclic aromatic hydrocarbons (PAHs) in petroleum-contaminated soils were 26000 mg / kg and 5300 mg / kg, respectively. The contents of alkanes and polycyclic aromatic hydrocarbons (PAHs) decreased to 12800 and 2900 mg / kg, respectively. The results showed that bioremediation combined with biological stimulation could effectively remove alkanes and PAHs from heavily petroleum contaminated soil. The total nitrogen content of soil changed from 1830 mg/kg to 1600 mg / kg, the content of ammonia decreased from 35.62 mg/kg to 1.22 mg / kg, the nitrate content decreased from 45.43 mg/kg to 7.17 mg / kg, and the soil enzyme activity was determined. The activities of soil dehydrogenase and polyphenol oxidase increased first and then decreased, while the activities of catalase and lipase increased significantly in the early stage of repair, and remained stable at the later stage of repair. The results of SPSS correlation analysis showed that, The removal efficiency of petroleum hydrocarbon and the content of nitrogen in different forms of soil during remediation. High throughput sequencing technique was used to analyze the changes of soil microbial community structure in different treatments in the later stage of remediation. The results showed that Actinobacteriae, Proteobacteria, Bacteroidetesa, Firmicuteset were the dominant bacteria in the oil-contaminated soil. The abundance of Promicromonospora, Pseudomonas sp., Mycobacterium Mycobacterium, Alterethrobacter alterethrobacter (Alterethrobacter alterethrobacter) and Alterethrobacter alterethrobacter (Alterethrobacter) increased significantly at the genus level.
【学位授予单位】：西安建筑科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S154;X53

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