MBR-蠕虫床-化学除磷联合系统污水处理及膜污染菌群解析

发布时间：2018-08-04 12:45

【摘要】：污水污泥的处理与处置显著增加污水处理成本,因此能够在污水处理过程中实现污泥同步减量的水处理工艺备受关注。课题组在前期研究中将MBR剩余污泥排入蠕虫床,通过蠕虫的捕食作用实现了污泥的高效减量、污泥性质的改良和膜污染的有效控制。为进一步深入分析MBR-蠕虫床联合系统中污染物去除、膜污染控制机制与微生物菌群变化的关系,解决联合系统污泥减量的同时所引发的磷释放问题,本研究以MBR-蠕虫床为研究对象,考察城市污水在联合系统各单元的去除情况和功能菌群变化,解析污泥形态结构、污泥特性和微生物菌群变化对膜污染的影响,构建MBR-蠕虫床-化学除磷联合系统,明确其优化控制条件,实现污水中磷的高效去除。联合系统中污染物去除与微生物菌群变化关系的研究表明:蠕虫床的捕食与代谢过程导致联合系统中MBR的化学需氧量(COD)、氨氮(NH4+-N)和总磷(TP)负荷分别增加0.8%、3.4%和11.3%,但联合系统中MBR对三者的去除率较传统MBR分别提高了2.0%、5.2%和1.7%,MBR-蠕虫床联合系统较传统MBR具有更高的污水处理效果;MBR-蠕虫床联合系统中,与蛋白质降解、碳水化合物转化和氨氧化有关的功能菌群得到了富集,其中Saprospiraceae bacterium、Klebsiella和Dechloromonas较传统MBR分别提高了4.0%、6.5%和5.9%,氨氧化菌(AOB)活性较传统MBR提高了11.6%。联合系统膜污染控制机制及其与微生物菌群变化关系的研究表明:与传统MBR相比,联合系统中污泥的沉降性提高了37.8%,污泥结构更加紧密,蛋白酶活性提高了19.1%,促进联合系统中关键膜污染物蛋白质的水解,使污泥混合液和泥饼层中胞外聚合物(EPS)中的蛋白质较传统MBR分别减少了33.6%和27.3%。同时,联合系统中的菌群与传统MBR相比,能大量分泌EPS或碳水化合物等胶体物质的Zoogloea、α-和β-proteobacteria分别降低了4.4%、2.3%和5.6%;可减缓膜污染的慢生菌Frankia、Clostridium和Actinomyces等提高了55.5%;可通过分泌蛋白质和多糖水解酶来降解可溶性微生物代谢产物(SMP)和EPS的Firmicutes bacterium、Flavobacterium和Chloroflexus分别提高了14.8%、8.3%和5.0%。综上,污泥结构、特性和菌群的变化使联合系统膜污染得到有效控制,其膜污染周期较传统MBR延长2.5倍以上。MBR-蠕虫床-化学除磷联合系统的构建及其运行效能的研究表明:化学除磷可使联合系统TP去除率达到20.8±3.3%,较MBR-蠕虫床提高19.6%,较传统MBR提高16.6%;化学除磷使蠕虫床中污泥的TP含量降低46.7%,酸性磷酸盐酶活性提高32.8%。通过化学除磷处理蠕虫床上清液及处理后的上清液回流至蠕虫床有效降低了蠕虫床上清液的COD和TP浓度,使MBR增加的COD和TP负荷分别减少了40%和72%,同时,化学除磷的加入降低了SMP中蛋白质和多糖浓度,增大了污泥絮体粒径,提高了污泥絮体的过滤性和脱水性,从而降低了化学除磷联合系统的膜污染速率。综上,MBR-蠕虫床-化学除磷联合系统实现了城市污水的高效处理与膜污染的有效控制,为生物捕食污泥减量技术与MBR的研究与应用提供了理论与技术支持。
[Abstract]:The treatment and disposal of sewage sludge greatly increase the cost of sewage treatment, so the water treatment technology that can reduce sludge synchronously during the process of sewage treatment has attracted much attention. In the previous study, the remaining sludge of MBR was discharged into the worm bed, and the high efficiency of sludge reduction, the improvement of sludge properties and membrane were realized by the predation of worms. Effective control of pollution. In order to further analyze the relationship between the removal of pollutants in the MBR- worm bed joint system, the relationship between the control mechanism of membrane pollution and the change of microbial flora, and to solve the problem of phosphorus release caused by the reduction of the sludge in the joint system, this study takes the MBR- worm bed as the study of the image and inspects the urban sewage in the unit of the joint system. The effects of sludge morphological structure, sludge characteristics and microbial flora change on membrane pollution were removed, and the MBR- chemical phosphorus removal combined system was constructed to clarify the optimal control conditions and to realize the efficient removal of phosphorus in sewage. The study on the relationship between the removal of pollutants and microbial flora in the combined system showed that the relationship between the removal of contaminants and microbial flora in the combined system showed that The predation and metabolism of worm bed lead to the chemical oxygen demand (COD) of MBR in the combined system, the increase of ammonia nitrogen (NH4+-N) and total phosphorus (TP) load by 0.8%, 3.4% and 11.3% respectively, but the removal rate of MBR to three in the combined system is 2%, 5.2% and 1.7%, respectively, compared with the traditional MBR, and the MBR- worm bed combined system has a higher sewage treatment efficiency than the traditional MBR. In the MBR- worm bed joint system, the functional bacteria related to protein degradation, carbohydrate transformation and ammoxidation have been enriched, and Saprospiraceae bacterium, Klebsiella and Dechloromonas are increased by 4%, 6.5% and 5.9% respectively compared with the traditional MBR, and the activity of ammonia oxidizing bacteria (AOB) is higher than that of the traditional MBR. The study of the mechanism and the relationship with the microbial flora showed that the sedimentation of the sludge in the combined system was increased by 37.8%, the sludge structure was more closely, the activity of the protease was increased by 19.1%, and the hydrolysis of the protein of the key membrane pollutants in the combined system was promoted, so that the sludge mixture and the mud cake layer were in the extracellular polymer (EPS) in the combined system, compared with the traditional MBR. Compared with the traditional MBR, the protein decreased by 33.6% and 27.3%. respectively. Compared with the traditional MBR, the bacteria in the combined system secreted Zoogloea of the colloid substances such as EPS or carbohydrate, and decreased the alpha and beta -proteobacteria by 4.4%, 2.3% and 5.6%, respectively, and increased the Frankia, Clostridium and Actinomyces by 55. to slow the membrane fouling. 5%, Firmicutes bacterium of soluble microbial metabolites (SMP) and EPS can be degraded by secreting protein and polysaccharide hydrolase, and Flavobacterium and Chloroflexus are increased by 14.8%, 8.3% and 5.0%. respectively. The sludge structure, characteristics and changes of bacteria groups make the combined system membrane fouling effectively control, and the membrane fouling cycle is more than the traditional MBR. The study on the construction and operation efficiency of 2.5 times longer.MBR- worm bed chemical phosphorus removal combined system shows that chemical removal of phosphorus can make the removal rate of TP in the combined system reach 20.8 + 3.3%, increase by 19.6% than that of MBR- worm bed, and 16.6% from the traditional MBR; chemical phosphorus removal reduces the TP content of sludge in worm bed by 46.7%, and the activity of acid phosphate enzyme increases 32.. 8%. effectively reduced the concentration of COD and TP in the supernatant of worm bed by chemical phosphorus removal and the reflux of the treated supernatant to the worm bed, which reduced the COD and TP load of MBR by 40% and 72% respectively. At the same time, the addition of chemical phosphorus reduced the concentration of protein and polysaccharide in SMP and increased the particle size of the sludge floc. The filtration and dehydration of the sludge floc reduces the membrane fouling rate of the chemical phosphorus removal combined system. In summary, the MBR- worm bed chemical phosphorus removal combined system realizes the effective treatment of urban sewage and the effective control of the membrane pollution. It provides theoretical and technical support for the research and application of biological prey sludge reduction technology and the research and application of MBR.
【学位授予单位】：哈尔滨工业大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：X703

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