改良A~2O-侧流除磷工艺脱氮除磷及微生物菌落特征研究

发布时间：2018-01-05 23:14

本文关键词：改良A~2O-侧流除磷工艺脱氮除磷及微生物菌落特征研究　出处：《中国海洋大学》2015年硕士论文　论文类型：学位论文

【摘要】：针对目前城镇污水低碳源脱氮除磷难,污泥处理处置难,城镇污水厂运行成本高等问题,本文提出一种新型组合式工艺改良A20-侧流除磷工艺,来解决城镇污水面临的难题。新型组合工艺应用改良A20为处理反应器,结合侧流除磷技术,以城市污水处理厂曝气沉砂池出水为处理对象,探讨系统在长污泥龄(SRT)低碳源、限氧曝气等条件下脱氮除磷效果,同时采用现代分子生物学技术解析侧流除磷过程中活性污泥微生物群落结构、组成与相对丰度变化。研究结果表明：1)采用限氧渐增方式曝气,合理分配溶解氧(DO),在降低33.3%曝气量情况下,系统有好的脱氮效果,其中COD、氨氮、TN去除率分别达到72%、95.8%、51.1%,出水浓度分别为27.5mg·L-1、0.65 mg·L-1、15.1 mg·L-1;2)在A20厌氧前端增设小段缺氧池可以很好的反硝化降低硝酸根浓度,使其浓度小于1.5 mg·L-1,减轻了硝酸根对厌氧释磷的抑制作用；3)污泥外循环侧流量越大,TP去除效果越好,回流点为缺氧池时系统TP去除效果要好于厌氧池、好氧池；4)侧流除磷和厌氧缺氧好氧交替变化可以富集强化聚磷菌(PAOs)和反硝化聚磷菌(DNPAOs),侧流后DNPAOs占PAOs,总量的84%,TN去除率由侧流前的51.1%升高到侧流后的61.1%,TP去除率由35.5%升高到92.7%,但侧流前后COD、NH4+-N去除无显著差异,去除率分别在74%、95%左右。另外,这种结合工艺可以实现污泥减量化和解决除磷菌与脱氮菌之间的生长代时矛盾。微生物群落分析发现,侧流改变了反应器细菌群落结构及微生物种类组成相对丰度发现。侧流除磷后,反硝化除磷微生物Thauera spp和Dechloromonas spp.丰度值分别提高至9.0%和8.5%,而Acinetobacter spp.丰度值从8.9%下降至1.2%。综合结果表明,将侧流除磷技术与改良A20工艺相结合,可以富集反硝化除磷菌,提高聚磷菌释磷能力。同时可以解决除磷菌与脱氮菌之间的泥龄矛盾,实现在长污泥龄(140d)下稳定去除污染物,使出水水质基本满足城镇污水排放—级A标准。
[Abstract]:In view of the problems of low carbon source nitrogen and phosphorus removal, sludge treatment and disposal, and high operating cost of urban sewage plant, a new combined process was proposed to improve the A20-side flow phosphorus removal process. The new combined process uses modified A20 as the treatment reactor, combined with the side flow phosphorus removal technology, and takes the effluent from the aeration sand settling tank of the municipal sewage treatment plant as the treatment object. The effect of denitrification and phosphorus removal by the system under the condition of low carbon source and limited oxygen aeration was discussed. Meanwhile, the microbial community structure of activated sludge in the process of side flow phosphorus removal was analyzed by modern molecular biology technology. The results show that the system has good denitrification effect under the condition of reducing the aeration rate by reducing the aeration rate of 33.3%. The removal rates of COD, NH3-N and TN reached 722 ~ 95.8% and 51.1% respectively, and the effluent concentration was 27.5mg 路L ~ (-1) and 0.65 mg 路L ~ (-1) respectively. 15.1 mg 路L -1; 2) adding a small section of anoxic cell to the front end of A20 can reduce nitrate concentration to less than 1.5 mg 路L ~ (-1), which can reduce the inhibitory effect of nitrate on anaerobic phosphorus release; 3) the removal effect of TP is better with the increase of the flow rate of sludge outer circulation side, and the removal efficiency of TP is better than that of anaerobic pond and aerobic pool when the reflux point is anoxic pool. (4) alternate variation of phosphorus removal and anaerobic anoxic aerobic activity can enrich Phosphorus-accumulating bacteria and denitrifying phosphorus-accumulating bacteria DNPAOs.After side flow, DNPAOs accounts for 84% of the total. TN removal rate increased from 51.1% before the side flow to 61.1% TP after the side flow, but the removal rate of TP increased from 35.5% to 92.7%, but the COD increased before and after the side flow. The removal rate of NH4-N was about 95% or so. The combined process can realize sludge reduction and solve the contradiction between phosphorus removal bacteria and denitrifying bacteria. The relative abundance of bacteria community structure and microbial species composition was found in the side flow, and phosphorus was removed by the side flow. The abundance of denitrifying phosphorus removal microorganism Thauera spp and Dechloromonas SPP. Increased to 9.0% and 8.5% respectively. However, the abundance of Acinetobacter SPP. Decreased from 8.9% to 1.2. The results showed that the side flow phosphorus removal technology was combined with the modified A20 process. It can enrich denitrifying phosphorus removal bacteria, improve the phosphorus release ability of phosphorus accumulating bacteria, solve the mud age contradiction between phosphorus removal bacteria and denitrification bacteria, and realize the stable removal of pollutants under the condition of 140 days of long sludge age. The effluent quality basically meets the class A standard of urban sewage discharge.
【学位授予单位】：中国海洋大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X703

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