自(异)养脱氮在低C/N污水处理厂的应用实践  

Application Practice of Autotrophic(Heterotrophic)Denitrification in a WWTP with Low C/N Ratio Influent

作　　者：蒋富海 JIANG Fu-hai(CSD Water Service Co.Ltd.,Beijing 100192,China)

机构地区：[1]中持水务股份有限公司,北京100192

出　　处：《中国给水排水》2021年第12期124-131,共8页China Water & Wastewater

摘　　要：低C/N污水处理厂面对碳氮高标准尾水提标要求时,宜采用异养反硝化与自养脱氮滤池的串级。自养脱氮滤池的脱氮效率易受系统进水水温、DO、NO_(3)^(-)-N负荷等影响,当进水水温为25~30℃、NO_(3)^(-)-N<15 mg/L、HRT>20 min时,滤池脱氮负荷达到0.56 kgTN/(m^(3)·d),脱氮率约60%,对应活性滤料消耗量与TN削减量之比为3.9,进水DO超过2 mg/L时会导致部分硫核滤料被氧化而无效消耗,可辅助投加Na_(2)S_(2)O_(3)作为电子供体。选用粒径为2.0~3.5 mm的改性硫核活性滤料,辅以适量砂料的双料复合滤层,以确保TN和SS的协同削减,且自养滤料节药效益明显。自养脱氮滤池需长期关注低水温时的脱氮效率,以及SO_(4)^(2-)、H_(2)S、NO_(2)^(-)-N等副产物是否积累。自养滤料的微生物优势菌落为Thiobacillus和Sulfurimonas两类硫杆菌,二者丰度之和超过50%。It’s recommended for the wastewater treatment plant(WWTP)with low C/N ratio influent to use cascade process of heterotrophic denitrification and autotrophic denitrification filter,so as to achieve high discharge standard.Nitrogen-removal efficiency of autotrophic denitrification filter is easily affected by influent temperature,DO,and NO_(3)^(-)-N load.When influent temperature is within 25to 30℃,influent NO_(3)^(-)-N concentration is less than 15 mg/L,and HRT of filter is above 20 minutes,the filter’s denitrification-load could be 0.56 kgTN/(m^(3)·d)and TN removal efficiency reached 60%,meanwhile the ratio of active media consumption to TN reduction is about 3.9.When the influent DO exceeded 2 mg/L,the sulfur-based filter media would be partly oxidized and consumed inefficiently.Thus,Na2S2O3could be added as an auxiliary electron donor.Activated sulfur-based autotrophic filter media with particularly size of 2.0 to 3.5 mm,supplemented with double layer composite quartz-sand,was selected to ensure the collaborative reduction of TN and SS pollutants,and to attain obvious benefits of chemical saving by using the autotrophic filter media.Long term attention should be paid to the nitrogen removal efficiency at low water temperature and whether the by-products such as SO_(4)^(2-),H_(2)S and NO_(2)^(-)-N were accumulated in the autotrophic denitrification filter.The dominant microbial colonies of autotrophic filter media were Thiobacillus and Sulfurimonas,and the abundance of both was more than50%.

关 键 词：低C/N比 异养反硝化 硫自养反硝化 自养脱氮滤池 深度脱氮除碳 

分 类 号：TU992[建筑科学—市政工程]