2-溴乙烷磺酸钠对ABR反应器运行效果和微生物菌群结构的影响

Effect of 2-Bromoethane Sulfonate on Operational Performance and Microorganism Structure of Anaerobic Baffled Reactor

针对厌氧反应器酸化问题,研究了2-溴乙烷磺酸钠(2-bromoethane sulfonate,BES)对厌氧折流板反应器(ABR)运行效果、中间代谢产物挥发性脂肪酸(VFA)及微生物群落结构的影响。结果表明,BES会导致ABR反应器处理效能降低,当BES投加量为0.27mmol/L时,CODCr去除率由95%降到10%以下。BES的投加加剧了ABR反应器酸化风险,导致出水pH降到5.5以下,反应器内VFA明显积累,丁酸、戊酸和己酸等占VFA总量的36%以上,出水VFA浓度达到15.3mmol/L左右;此外,BES的投加导致产甲烷菌的相对丰度降低25%左右,而产氢产乙酸菌及耗氢产乙酸菌的相对丰度分别增加了9%和7%。PCR-DGGE和多样性指数结果表明,BES的投加显著影响了ABR反应器内各隔室的微生物种群结构,导致反应器的细菌种群多样性及丰富度指数均有所减少,优势微生物种群由厚壁菌门、杆菌属变为拟杆菌门、螺旋菌门及δ-变形菌门。

Theinfluence of 2-bromoethane sulfonate （BES） on the operational performance, intermediate metabolite- volatile fatty acid （VFA） and the microorganism population structure of the anaerobic baffled reaetor（ABR） was investigated, aiming at the acidification problem in anaerobic reactors. The results showed that BES could decrease the processing performance of ABR, and when the BES dosage was 0.27 mmol/L, the removal effieieney of CODcr decreased from 95% to 10% correspondingly. The addition of BES increased the acidification risk of ABR with the pH decreasing to 5.5 and VFA accumulating. The effluent VFA reached to about 15.3 mmol/L with butyric acid, pentanoie acid and hexanoie acid accounting for more than 36%. When BES was added, the relative abundance of methanogens decreased by 25 %, and that of hydrogen-producing acetogenic baeteria and homoacetogenie bacteria increased by 9% and 7%, respectively. The PCR-DGGE and Diversity Index also showed that while adding BES, the microorganism population structure in each compartment of ABR was affeeted significantly and the bacteria population diversity and richness decreased remarkably. Also, the dominant species changed from Firmicutes and Baeterium to Bacteroidetes, Spirochaetes and 8-proteobacteria.