【作者】 郭亚楠；

【导师】 罗湘南；

【作者基本信息】 河北科技大学 ， 环境科学与工程， 2011， 硕士

【摘要】 本研究以阿特拉津为目标污染物,通过实验室小试MBR和CAS反应器的运行,考察了MBR和CAS反应器中基因工程菌生物强化对阿特拉津去除效果以及常规污染物处理能力的影响;通过FISH技术分析了阿特拉津降解基因atzA基因在基因工程菌和土著菌株之间的转移情况;并通过PCR-DGGE分析了反应器不同运行阶段污泥微生物群落的变化。结果表明,基因工程菌生物强化实现了阿特拉津的高效生物去除,MBR和CAS阿特拉津平均去除率分别可高达88.6%和85.3%。阿特拉津生物强化去除有助于反应器保持较高的污泥生物活性。阿特拉津对常规污染物COD和氨氮的生物去除活性具有一定的抑制作用;基因工程菌生物强化后,COD及氨氮的去除效率得到恢复。在MBR和CAS反应器中,COD去除效率分别可高达96.0%和91.5%,氨氮去除效率分别可高达98.6%和95.7%。MBR对污染物的去除性能优于CAS。接种基因工程菌后,MBR和CAS反应器中基因工程菌密度快速下降后,逐渐保持稳定,稳定细胞密度分别为2.1×10~3CFU/mL和1.7×103CFU/mL。atzA基因平均相对丰度先减小而后增加,说明经过长期适应,atzA基因不仅存在于基因工程菌中,也转移至土著细菌细胞中。MBR和CAS反应器不同运行阶段污泥微生物群落具有一定差异。阿特拉津的存在降低污泥微生物群落的种群多样性和稳定性,而阿特拉津生物强化去除使得污泥微生物群落的种群多样性和稳定性有所恢复。MBR对于保持污泥微生物群落的种群多样性和稳定性具有一定的工艺优势。更多还原

【Abstract】 Atrazine and conventional pollutants removal bioaugmented by genetically engineered microorganism (GEM) were investigated in this study in both membrane bioreactor (MBR) and conventional activated sludge reactor (CAS). Fluorescence in situ hybridization (FISH) was used to analyze the transfer of atzA gene between GEM and indigenous strains. The polymerase chain reaction and denaturing gradient gel electrophoresis (PCR-DGGE) were used to analyze the microbial community variation of both reactors in different running stages.The results indicated that high removal efficiency of atrazine was obtained in both bioreactors bioaugmented by GEM. The average removal efficiencies of atrazine in MBR and CAS bioreactors reached up to 88.6% and 85.3%, respectively. Atrazine removal bioaugmented by GEM would be helpful to maintain high sludge bioactivity in both bioreactors. The removal activities of COD and ammonia nitrogen were inhibited a little by atrazine and recovered after bioaugmentation by inoculated GEM. In MBR and CAS bioreactors, the removal efficiencies of COD reached up to 96.0% and 91.5% respectively and the removal efficiencies of ammonia nitrogen reached up to 98.6% and 95.7%, respectively. The performance of MBR was better than CAS.The GEM density decreased quickly in both bioreactors after GEM inoculation and then became stable. The stable GEM densities in MBR and CAS were 2.1×10~3 CFU/mL and 1.7×103 CFU/mL, respectively. The average relative abundances of atzA gene decreased initially and increased subsequently, indicating that the atzA gene transferred into the indigenous strains after a long-term adaptation. Microbial community varied in different running stages of two bioreactors. The biodiversity and stability of microbial community decreased in the presence of atrazine and recovered after efficient atrazine removal was realized. MBR was better than CAS to maintain biodiversity and stability of microbial community.更多还原