城市污水条件下ASBR厌氧氨氧化的启动与脱氮性能

Start up of anaerobic ammonium oxidation process and nitrogen removal performance in anaerobic sequencing batch reactor for municipal sewage

采用ASBR在城市污水条件下进行厌氧氨氧化的启动与脱氮性能研究。实验接种好氧硝化污泥,在温度为(35±1)℃、HRT为24 h、pH为7.3～8.5的条件下经过130 d的培养,成功启动了厌氧氨氧化反应。实验结果表明,厌氧氨氧化反应稳定运行时,TN容积负荷平均为0.179 kg/(m3.d),NH4+-N、NO2--N和TN去除率分别达到了95.30%、91.30%和76.28%。启动期和稳定运行期NH4+-N、NO2--N去除量和NO3--N生成量的比值分别达到1∶1.54∶0.25和1∶1.27∶0.27;稳定运行期进出水pH差值由启动时的0.85下降到0.24。启动期反硝化和厌氧氨氧化反应同时存在而在稳定运行期厌氧氨氧化发展成为主导反应。MLSS和MLVSS/MLSS先减少后增加,反映了启动过程中硝化细菌、反硝化细菌的衰亡和厌氧氨氧化菌逐渐富集的过程,这与反应器的宏观运行效果相一致。

Starting up of anaerobic ammonium oxidation （ANAMMOX） and nitrogen removal performance were studied in an anaerobic sequencing batch reactor （ASBR） treating the municipal sewage. Inoculated with nitrifying sludge, the anaerobic ammonium oxidation was started up successfully for 130 d in the anaerobic se-quencing batch reactor. The experimental conditions were as follows ： temperature of （35 ± 1 ） ℃ , HRT of 24 h and pH of 7.3 - 8.5. Experimental results indicated that when the average volumetric load of total nitrogen was 0. 179 kg/（m^3· d）, the average removal rates of NH4-N, NO2^--N and TN were 95.30%, 91.30% and 76.28% ,respectively at stable stage. The ratio of ammonium removal, nitrite removal and nitrate increase was 1： 1.54：0.25 at start-up stage, and it was 1： 1.27：0.27 at stable stage. The pH increment between influent and effluent changed from 0.85 at start-up stage to 0.24 at stable stage. Denitrification and ANAMMOX were existed simultaneously at start-up stage, however, ANAMMOX became the dominant reaction at stable stage. MLSS and MLVSS/MLSS decreased at the beginning and then increased. The changing process reflected the decease of ni- trobacteria, denitrifying bacteria and the enrichment of ANAMMOX bacteria. This was in concert with nitrogen removal performance.