低温脱氮菌剂的制备及其强化人工湿地脱氮效能研究

发布时间：2018-06-09 05:08

本文选题：人工湿地 + 低温脱氮菌剂　；参考：《哈尔滨工业大学》2015年硕士论文

【摘要】：人工湿地技术以其低耗高效、绿色生态的优点在生活污水的深度处理方面具有广阔的应用前景,但在我国北方寒冷地区,冬季时气温较低,人工湿地处理污水的脱氮效能明显下降。本文从开发低温下具有较高脱氮效能的微生物菌种出发,构建低温脱氮菌剂,研究低温生物强化技术在人工湿地污水处理中的应用,并对低温脱氮菌的作用进行群落结构解析,为低温脱氮菌的工程应用和菌剂构建奠定一定的理论基础。通过富集驯化低温脱氮菌群,并对低温脱氮菌群进行效能评价发现,富集的低温硝化菌群和低温好氧反硝化菌群在10oC下具有较高的脱氮效能,均为耐低温菌。其中低温硝化菌群在氨氮浓度为21.35 mg/L时的硝化效能最好,对氨氮的去除率可达85.62%;好氧条件下,低温好氧反硝化菌群在硝氮浓度为20.14mg/L、碳氮比为5.05时的反硝化效能最好,对硝氮和总氮去除率分别可达55.41%和30.43%,在厌氧条件下,低温好氧反硝化菌群也具有反硝化效能,在硝氮浓度为18.53 mg/L、碳氮比为5.88时的反硝化效能最好,对硝氮和总氮的去除率分别可达95.68%和58.73%。研究低温脱氮菌强化人工湿地的脱氮效能发现,生物强化且水力停留时间为24 h时,相比于对照系统,强化系统的出水氨氮和总氮去除率分别提高了约16.32%和16.41%,强化系统的出水氨氮和总氮浓度分别为7.96 mg/L左右和12.77 mg/L左右,基本能够达到《城镇污水处理厂污染物排放标准》的一级A标准;生物强化并缩短水力停留时间为12 h时,相比于对照系统,强化系统出水氨氮和总氮去除率分别提高了约24.46%和24.56%,强化系统的出水氨氮和总氮浓度平均可达7.29 mg/L和12.93 mg/L,能够达到《城镇污水处理厂污染物排放标准》的一级A标准,从而在减少出水中副产物的同时增加了日处理量。解析低温脱氮菌的作用发现,低温脱氮菌群中含有Pseudomonas、Bacillus、Flavobacterium、Nitrosomonas和Nitrobacter等具有脱氮功能的微生物菌属,与对照系统相比,在强化系统中以上具有脱氮功能微生物的含量有所增加,从而使强化系统的出水氨氮和总氮浓度降低。Pseudomonas、Bacillus和Nitrosomonas以及土壤中Nitrospira的含量增加比例较大,可以为低温脱氮菌剂的构建提供理论依据。
[Abstract]:Artificial wetland technology has broad application prospect in advanced treatment of domestic sewage with its advantages of low consumption and high efficiency and green ecology. However, the temperature in winter is relatively low in cold areas of northern China. The nitrogen removal efficiency of constructed wetland for wastewater treatment was obviously decreased. In this paper, a low temperature denitrification agent was constructed based on the development of microbial species with high denitrification efficiency at low temperature. The application of low temperature biological intensification technology in wastewater treatment of constructed wetland was studied, and the community structure of low temperature denitrification bacteria was analyzed. It lays a certain theoretical foundation for the engineering application of low temperature denitrifying bacteria and the construction of bacteria agent. Through enrichment and acclimation of low temperature denitrification bacteria, and evaluation of the efficiency of low temperature denitrification bacteria, it was found that the enriched low temperature nitrifying bacteria and low temperature aerobic denitrifying bacteria had higher denitrification efficiency at 10oC, both of them were low temperature tolerant bacteria. The nitrification efficiency of low temperature nitrifying bacteria was the best when ammonia concentration was 21.35 mg / L, and the removal rate of ammonia nitrogen reached 85.62.The denitrification efficiency of denitrifying bacteria at low temperature aerobic denitrification was 20.14 mg / L and the ratio of carbon to nitrogen was 5.05 under aerobic condition. The removal rates of nitrate and total nitrogen were 55.41% and 30.43%, respectively. The denitrification efficiency of aerobic denitrifying bacteria at low temperature was also obtained under anaerobic conditions. The denitrification efficiency was the best when the nitrate concentration was 18.53 mg / L and the C / N ratio was 5.88. The removal rates of nitrate and total nitrogen were 95.68% and 58.73%, respectively. The denitrification efficiency of low temperature denitrifying bacteria enhanced constructed wetland was studied. The results showed that the denitrification efficiency of the constructed wetland was better than that of the control system when the biological enhancement and hydraulic retention time was 24 h. The effluent ammonia nitrogen and total nitrogen removal rate of the enhanced system were increased by 16.32% and 16.41%, respectively. The effluent ammonia nitrogen and total nitrogen concentration of the enhanced system were about 7.96 mg / L and 12.77 mg / L, respectively. In comparison with the control system, the first class A standard of pollutant discharge standard for municipal wastewater treatment plants can be basically achieved, and when the hydraulic retention time (HRT) is shortened by 12 h, The removal rates of ammonia nitrogen and total nitrogen in the effluent of the enhanced system increased by 24.46% and 24.56%, respectively. The effluent ammonia nitrogen and total nitrogen concentration of the enhanced system reached an average of 7.29 mg / L and 12.93 mg / L, respectively. The effluent ammonia nitrogen and total nitrogen removal rate of the enhanced system could reach the first class A standard of the pollutant discharge standard of the municipal wastewater treatment plant. As a result, the by-products in the effluent are reduced and the daily treatment capacity is increased. By analyzing the effect of low temperature denitrification bacteria, it was found that the low temperature denitrification bacteria contained Pseudomonas spp. Flavobacterium nitrosomonas and Nitrobacter. Compared with the control system, the contents of the above denitrification bacteria in the enhanced system were increased. Thus, the concentration of ammonia nitrogen and total nitrogen in the effluent of the enhanced system decreased. The contents of Pseudomonas Bacillus and Nitrosomonas and Nitrospira in soil increased by a large proportion, which could provide theoretical basis for the construction of low temperature denitrification bacteria.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X703;X172

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