驯化复合微生物菌群处理废弃钻井泥浆活性研究

Treatment of waste drilling mud by domesticated complex microbial flora

摘要:

[背景]油田废弃钻井泥浆含油量高，污染物复杂，环境危害严重，现有技术无法满足日益发展的石油开采行业在废弃钻井泥浆处理方面的需求。生物法处理废弃钻井泥浆，工艺简单，成本低，但也存在局限，包括广谱性差、处理周期长、原油降解率低、泥浆性质波动冲击工艺稳定性等。[目的]构建一种高活性和高环境耐受能力的微生物菌群，分析遗传稳定性和综合性能，提高废弃钻井泥浆处理技术水平。[方法]通过定向富集、诱导驯化的方法，提高活性群落对石油烃乳化降解效率，降低共代谢底物反馈抑制和群体感应系统敏感度，分析群落结构和活性成员的种群类别，分析乳化降解石油烃的活性对应关系。[结果]从含油量超过12 g/kg、芳烃-胶质沥青含量超过80%、含盐量超过8 g/kg的钻井废弃泥浆中富集得到1个活性微生物菌群，主要成员包括假单胞菌属（Pseudomonas）、根瘤菌属（Rhizobium）、红细菌属（Rhodobacter）和嗜碱还原硫素杆菌（Dethiobacter alkaliphilus），比例分别达27.44%、20.73%、8.54%和7.93%。在超过22代的连续驯化过程中，假单胞菌（Pseudomonas）、类希瓦氏菌（Alishewanella）和盐单胞菌（Halomonas）数量达92.72%，菌群结构和活性趋于稳定。处理钻井废弃泥浆5 d，土壤含油率由处理前的12403 mg/kg降低到处理后的42 mg/kg，综合脱油效率99.67%，石油烃降解率68.9%。分析微生物群落作用前后石油饱和土壤中的石油含量变化，原始含油量261 g/kg，处理后含油量305 mg/kg，脱油率99.88%。[结论]菌群驯化后活性稳定，耐受高盐环境能力强，在钻井废弃泥浆、含油土壤及油泥污染物处理方面具有很强的工业应用潜力。

Abstract:

[Background] The waste drilling mud in the oil field has high oil content, complex pollutant and serious environmental hazards, and existing technologies cannot meet the requirements of the increasingly developed petroleum exploitation industry in the treatment of waste drilling mud. Biological treatment of waste drilling mud has the advantages of simple process and low cost, but it also has some limitations, including poor broad-spectrum, long processing cycle, low petroleum degradation rate and the fluctuation of sludge properties affects the active stability. [Objective] To improve the biological treatment of waste drilling mud, a microbial community with high activity and high environmental tolerance was constructed, and the comprehensive performance and genetic stability was analyzed. [Methods] Through directional enrichment, induction and acclimation methods, the efficiency of petroleum hydrocarbons emulsification and degradation was expected to be improved, and the feedback inhibition of co-metabolic substrate and quorum sensing system sensitivity were expected to be reduced. We analyzed the structure and the active members' types of the microbial community, and studied the corresponding relationship with emulsification-degradation of petroleum hydrocarbons. [Results] An active microbial community was enriched from drilling waste mud containing more than 12 g/kg oil, more than 80% aromatics-colliod-asphalt and more than 8 g/kg salt. The main members include Pseudomonas, Rhizobia, Rhodobacter and Dethiobacter alkaliphilus, with the ratio of 27.44%, 20.73%, 8.54% and 7.93%, respectively. During the continuous acclimation of more than 22 generations, the quantity of Pseudomonas, Alishewanella and Halomonas was accounted for more than 92.72%, the structure and activity of the microbial community was stable. When the waste drilling mud was treated for 5 days by the active community, the oil content of soil decreased from 12403 mg/kg to 42 mg/kg, the comprehensive oil removal efficiency was 99.67%, and the petroleum hydrocarbon degradation rate was 68.9%. The content in crude oil saturated soil was analyzed before and after microbial community action, the original oil content was 261 g/kg, and the oil content after treatment was 305 mg/kg, deoiling rate was 99.88%. [Conclusion] After acclimation, the microbial community has stable activity, strong tolerance to high salt environment, the active microbial community has strong industrial application potential in drilling waste mud, oily soil and sludge pollutant treatment.