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

Abstract:

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.