对硝基苯酚冲击对UASB反应器中污泥活性和微生物种群的影响

研究了在稳定运行的上流式厌氧污泥床(Upflow Anaerobic Sludge Blanket,UASB)反应器中,对硝基苯酚(p-NP)冲击对反应器活性的影响。采用PCR-DGGE技术监测了反应器受对硝基苯酚冲击后微生物种群多样性的变化。实验结果表明,p-NP冲击对污泥的产甲烷活性和COD去除活性均有严重的抑制,污泥活性的恢复需要较长时间;高浓度冲击比低浓度冲击产生更严重的影响,20mg/L和40mg/Lp-NP冲击后污泥活性的恢复期分别为16d和27d。p-NP冲击后,真细菌和古菌的多样性均发生了显著的变化,而且p-NP冲击对真细菌的影响大于对古菌的影响。p-NP冲击后甲烷产量下降的主要与Methanosaetasp.的活性下降以及Methanomicrobia sp.丰度的下降有关。而冲击后真细菌的主要变化表现为Chloroflexisp.、Bacteroidesp.和Anaerovibrio sp.的丰度均下降;Rheinheimera sp.在受到20mg/Lp-NP冲击时丰度下降,继续受到40mg/Lp-NP冲击时该种群消失。Flavobacteria sp.是p-NP冲击后新出现的细菌种群,可能与p-NP的降解有关。

Effect of p-nitrophenol Shock on Sludge Activity and Microbial Populations and in UASB Reactor

Effect of p-nitrophenol shock on microbial populations and sludge activity in UASB reactor was studied by DGGE-PCR of 16S rDNA fragments and detection of COD removing and biogas yield. The results showed that p-nitrophenol seriously inhibited the sludge activity, resulting in the drop of biogas and COD removing rate. The 40mg/L p-nitrophenol had more inhibition than 20mg/L p-nitrophenol. It would take 27 and 16 days respectively for reactor to recover after 40mg/L and 20mg/L p-nitrophenol shock. The diversity of eubacteria and methanogens were also effected by the p-nitrophenol shock. The variation of eubacteria was more than that of methanogens after p-nitrophenol shock. The drop of biogas was mainly related to the variation of Methanosaeta sp. and Methanomicrobia sp. after p-nitrophenol shock. Among the eubacteria the population of Chloroflexi sp. ,Bacteroide sp. and Anaerovibrio sp. decreased greatly after p-nitrophenol shock. And more, the Rheinheimera sp disappeared after 40mg/L p- NP treatment. But the Flavobacteria sp. appeared after p-nitrophenol shock, which was probably related to the degradation of p-NP.