低C/N值污水强化生物脱氮性能研究  

Enhanced Biological Nitrogen Removal Performance of Low Carbon to Nitrogen Ratio Wastewater

作　　者：李航 董立春[1] 吕利平[3] LI Hang;DONG Li-chun;Lü Li-ping(School of Chemistry and Chemical Engineering,Chongqing University,Chongqing 401331,China;Chongqing Three Gorges Water Yubei Drainage Co.Ltd.,Chongqing 401120,China;College of Chemistry and Chemical Engineering,Yangtze Normal University,Chongqing 408100,China)

机构地区：[1]重庆大学化学化工学院,重庆401331 [2]重庆市三峡水务渝北排水有限责任公司,重庆401120 [3]长江师范学院化学化工学院,重庆408100

出　　处：《中国给水排水》2022年第7期80-85,共6页China Water & Wastewater

基　　金：重庆市教委科学技术研究计划青年项目(KJQN20211417)。

摘　　要：采用改良型A^(2)/O工艺处理低C/N值城市污水,在具体工程实例中考察了内回流比与DO浓度对生物脱氮效果的影响。在此基础上,采取外加碳源的方式强化出水氮素指标的可控性。结果表明,适当增大内回流比有利于提高总氮去除率,但过高的内回流比会提升缺氧区DO浓度,不利于反硝化反应的进行;降低DO浓度有利于总氮的去除,但会对好氧区硝化反应产生抑制作用,导致氨氮的转化受到影响。基于所采用的5种内回流比与5种DO工况,选出的较为合适的内回流比为275%、DO为1.2~1.5 mg/L,在辅以外加碳源的情况下,出水总氮平均浓度能降至9.20 mg/L,氨氮平均浓度为0.38 mg/L,出水氮素指标显著优于一级A排放标准。投加碳源不会对出水COD产生明显影响,外加碳源对成本的贡献仅为0.11元/m^(3),且对出水水质指标可实现更加稳健的控制,有效促进了成本与水质的双赢。A modified A^(2)/O process was employed to treat municipal wastewater with low carbon to nitrogen ratio(C/N),and the effects of internal reflux ratio and dissolved oxygen(DO)on biological nitrogen removal in an engineering project were investigated.On this basis,addition of carbon source was adopted to enhance nitrogen removal.Appropriately increasing the internal reflux ratio was beneficial to improve the total nitrogen removal efficiency.However,too high internal reflux ratio would increase the DO in the anoxic zone,which was not conducive to denitrification.The decrease of DO was beneficial to the removal of total nitrogen.However,it would inhibit the nitrification reaction in the aerobic zone,which affected the transformation of ammonia nitrogen.Among the five internal reflux ratios and five DO operating conditions,the optimal internal reflux ratio and DO were 275% and 1.2-1.5 mg/L.With the aid of dosing carbon source,the average concentration of total nitrogen in the effluent was reduced to 9.20 mg/L,and the average concentration of ammonia nitrogen was 0.38 mg/L,indicating that the effluent nitrogen indexes were significantly better than the first level A criteria specified in the Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant(GB 18918-2002).The addition of carbon source did not have a significant impact on the effluent COD,and the contribution of additional carbon source to the cost was only 0.11 yuan/m^(3).In addition,a more robust control of the effluent index was achieved,which effectively promoted a win-win between cost and water quality.

关 键 词：低C/N值污水 生物脱氮 内回流比 溶解氧 外加碳源 氮素 

分 类 号：TU992[建筑科学—市政工程]