处理印染废水的厌氧折流板反应器中的微生物种群组成及分布规律

设计出一个由12个隔室组成的厌氧折流板反应器(ABR),并将其应用于高浓度、高色度的印染废水生物处理,取得了良好效果。研究着重考察该反应器在处理印染废水过程中不同隔室的微生物种群构成,并分析与印染废水处理效率密切相关的具有脱色功能和苯胺降解功能的两类细菌的分布规律。结果表明,在处理印染废水的ABR反应器中,可培养的优势菌群以芽孢杆菌属(Bacillus)、不动杆菌属(Acinetobacter)、丛毛单胞菌属(Comamonas)、假单胞菌属(Pseudomonas)和水螺菌属(Aquaspirillum)为主,且在ABR的前段、中段及后段隔室中不同种类的优势菌群存在数量差异;好氧及兼性厌氧优势菌群的数量随着废水在ABR隔室中的折流前进而逐渐减少;厌氧微生物的数量变化规律则是先增多,后减少;产甲烷活性在前段隔室中相对较低,后段隔室则相对较高。脱色菌在ABR的前段隔室中分布相对较多,后段隔室中分布相对较少;苯胺降解菌则呈现出在前段隔室中分布相对较少,后段隔室中分布相对较多的规律,这两类功能菌的分布与ABR不同隔室中色度下降、苯胺产生和消减之间密切相关。

The microbial population in an anaerobic baffled reactor for the treatment of dye wastewater

An anaerobic baffled reactor (ABR) provides spatial separation between acidogenic and methanogenic populations, and thus allows different bacterial groups to develop under their optimal conditions. It essentially behaves as a two-phase system. Most of the past studies on microbial populations had focused on methanogenesis. The most common observation is a shift between the two acetoclastic methanogens Methanosarcina sp. and Methanosaeta sp. However, little has been done on the population of acidogenesis. Besides, there are very few examples of using ABR to treat printing and dyeing wastewater although it is known that anaerobic process is a promising alternative to decolorize the dye waste. In this study a 4L ABR containing 12 compartments was used to treat high strength, dark printing and dyeing wastewater. It has internal dimensions of 1200 mm long, 100 mm wide and 400 mm deep. The objective of this study was to identify and quantity the dominant populations in the sludge of each compartment, as well as to analyze the distribution of the physiologically important population members: decolorizing bacteria and aniline-degrading strains. The genus of Bacillus,Acinetobacter,Comamonas,Pseudomonas and Aquaspirillum are the dominant population. Bacillus is the most dominant, and followed by Acinetobacter and Comamonas. In fact, the population of each genus is different various compartments. At the front end, the microbial quantity is higher, but the main population decreases in number toward the end of ABR. The populations of anaerobes in each compartment were analyzed by both plate count under anaerobic station and measurement of methane production rate. The anaerobic populations increase firstly, and then decrease. More than 547 strains, including 174 dyes degrading and 231 aniline-degrading strains, were screened and analyzed for their decolorization and aniline-degrading abilities. The results indicate that a higher decolorizing population existed in the front than in the rear compartments. On the other hand, the aniline-degrading strains were less in the front and more in the rear compartments. The aniline content and its color density in different compartments were also analyzed. The results show that the aniline concentration increased with the degradation of azo dyes by the decolorizing strains in the treatment process. This allowed more aniline-degrading strains to develop, resulting in more aniline degradation under the anaerobic condition prevailing in the second half of ABR. The concentration of aniline was the highest when wastewater was being decolorized,then it gradually decreased. These results provide a useful basis for the ABR process optimization in high strength, dark color printing and dyeing wastewater.