Analysis Of Microbiology Community In Nonylphenol Ethoxylates-enriched Avtived Sludge

Nonylphenol ethoxylate is a kind of non-ionic surfactant, which is widely used in the industries of paper-making, rubber, plastics and cleanser, and is closely related to our daily life. After its access to water, its main degradation products is nonylphenol, which is a kind of endocrine disrupting chemical which can cause adverse effects to organisms.In the experiment, A/O process is used. In optimal conditions, micro-biological degradation of NP10EO by A/O process is evaluated, as well as NP10EO degradation flora is cultured.The experimental results show that the state of activated sludge will be affected with increase of NP10EO in raw water. But with the adaption of activated sludge, the state will gradually be improved and indicators of the state of activated sludge will be more stable. When the density of NP10EO becomes higher, various indicators of water quality will also be impacted. Removal rate of COD will drop. While the concentration of NP10EO being stable, removal rate of COD will rebound. Removal of NP10EO by A/O process is obvious after a short-term acclimation. But change of concentration of NP10EO will lead to substantial change of removal rate. During the course, ultimate micro-biological degradation of NP10EO will happen and the structure of benzene ring will be destroyed. Both ultimate micro-biological degradation and adsorption of activated sludge lead to satisfying removal rate.In this study, polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) and fluorescence in site hybridization (FISH) with oligonucleotide probes were used to investigate microbial community structure in activitied sludge of A/O reactor.It is found that with concentration changes of NP10EO in raw water structure of microbial flora will change too. The number of bands in DGGE will decrease. However, with the stability of concentration of NP10EO, dice coefficient of the two pools will increase. The structure of microbial flora will be relatively stable. And ultimately we get the microbial flora that adapt for degradation of NP10EO and its intermediate products. Members of gamma subclass of Proteobacteria were present in low numbers in all activated sludge samples examined, suggesting that only bacteria affiliated with the beta subclass of Proteobacteria may have a specific role in NP10EO degradation.