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Effect of P-nitrophenol and Organic Loading Shock on Sludge Activity and Microbial Community in UASB Reactor

Author: MeiQin
Tutor: ShenBiao
School: Nanjing Agricultural College
Course: Microbiology
Keywords: Anaerobic biological treatment Nitrophenol impact The impact of organic load Activated Sludge Microbial species diversity
CLC: X703
Type: Master's thesis
Year: 2007
Downloads: 205
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Abstract

Anaerobic biological treatment technology with low energy consumption, low sludge production, nitrogen and phosphorus the less nutritional needs and produce biogas is an excellent energy and other prominent advantages, so that it has become an important means of control of organic pollution in China. In biological wastewater treatment device in normal operation but are often subject to the effects of changes in wastewater composition, such as new projects due to the factory, products the upgrading or production process debugging improper toxic compounds into the wastewater treatment plant, or a sudden increase of organic load. Peek into the varying degrees of impact caused by poison or organic load suddenly elevated to be a normal operation of the sewage treatment plant, sludge decreased activity, decreased water quality. Study of toxic substances Therefore, the impact of the organic load of the microbial community in the anaerobic treatment device, in particular the impact of methane-producing bacteria, improved biological wastewater treatment process, to guide the operation and management of the anaerobic treatment device, and improve the efficiency of wastewater treatment has important guiding significance. This study is based on the stable operation of the upflow anaerobic sludge blanket reactor object anaerobic sludge total DNA extraction methods; different concentrations of nitrophenol and organic load impact on the reactor sludge activity and microbial community diversity. According to the number of extracted DNA purity and fragment size, the sludge after repeated freeze-thaw method combined with DNA extracted by SDS method than directly with the effect of SDS method; combination of SDS method of extraction effect the SDS method off than the ultrasonic liquid nitrogen grinding method better. Repeated freezing and thawing combined with DNA extracted by SDS method and analyzed by PCR-DGGE bands had the largest number, Shannon index, microbial community diversity up, indicating that the repeated freezing and thawing combined with SDS method is most suitable for anaerobic sludge DNA was extracted method. Molecular methods using PCR-RFLP analysis of the vaccination and domesticated mature sludge methanogenic bacteria community diversity, through the the Hae Ⅲ digested by Rsa Ⅰ type of analysis drawn, inoculated sludge of methanogen diversity than mature sludge. Mature sludge advantage of methanogenic bacteria Methanosaeta sp. The Methanomicrobia sp. Methanothrixsp., While the the seed sludge advantage of methanogenic bacteria Methanospirillum sp, Methanocorpusculum sp and Methanogenium sp., Two methanogenic sludge bacterial community structure vary greatly. Anaerobic reactor of COD _Cr removal rate, methanogenic activity was inhibited UASB reactor by 20mg/Lp-NP, and 40mg/Lp-NP impact, sludge decreased activity; high concentration The impact on the system of p-NP impact than the impact of the low-concentration p-NP system convalescence is 27d, 11d of impact than the low-concentration p-NP long recovery period. PCR-DGGE analysis showed that p-NP is a significant impact, the impact on the microbial community diversity and greater than the impact of archaea and bacteria. Filamentous bacteria green sulfur bacteria (Chloroflexi), the acid-producing bacteria anaerobic Vibrio genus (Anaerovibrio sp.) And Bacteroides spp (Bacteroide sp.) The greatest impact, its abundance change a lot. Flavobacterium (Flavobacteria sp.) Is added after the impact of the p-NP case, it may be related to the degradation of the p-NP. Impact increased by 50%, 100%, 150% and 200% of the organic load, COD _Cr removal rate fluctuations, methanogenic activity affected; bacteria by PCR-DGGE analysis system and archaeal community structure did not change a lot; quantitative PCR detection of methane-producing bacteria, draw the number of methanogenic 9.51 × 10 ^{9 ~ 5.6 × 10 ^{10 cells / g dry sludge, methanogenic bacteria count differences in each shock load. P-NP impact and the impact of organic load, the anaerobic sludge microbial physiology flora, the results show the impact of p-NP, fermentative bacteria and acetogenic bacteria hydrogen production decline in the number of two orders of magnitude, production the methanogens declined by only an order of magnitude further illustrate the impact of the p-NP bacteria than archaea; impact of organic load, three types of flora, are an order of magnitude, but also explains the toxic substances impact than the impact of organic loading a large impact on the system.}}

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