ANAMMOX富集与优化停曝比对MBR-SNAD工艺的影响

Effect of ANAMMOX enrichment and optimization of non-aeration/aeration ratio in MBR-SNAD process

采用膜生物反应器(MBR)研究了厌氧氨氧化细菌在富集过程中的活性变化,在启动全程自养脱氮(CANON)工艺中以恒定曝气量,通过优化停曝比实现氨氧化细菌(AerAOB)和厌氧氨氧化细菌(An AOB)协同脱氮并且有效抑制亚硝酸盐氧化菌(NOB)的活性,然后添加有机物(乙酸钠)逐步启动同步亚硝化-厌氧氨氧化耦合异养反硝化(SNAD)工艺.结果表明,在厌氧氨氧化细菌富集过程中,通过不断缩短水力停留时间(HRT)提高进水氮负荷的方式强化厌氧氨氧化细菌活性,其平均活性由0.603mgN/(h·gVSS)提高到了8.1mgN/(h·gVSS);当恒定曝气量为50mL/min,停曝比为4:10(min:min)时,AerAOB和An AOB对氨氮的去除量分别占总氨氮去除量的58.8%和41.2%, NOB氧化亚硝态氮的量占总硝态氮生成量的15.3%,成功抑制了NOB的活性;当C/N比为0.5,调整停曝比为4:15后,反硝化过程氮去除量占总氮去除率的20.9%,厌氧氨氧化过程氮去除量占总氮去除率的79.1%,实现了Aer AOB、An AOB和反硝化细菌(DNB)协同脱氮的目的.

The activity changes of anaerobic ammonia-oxidizing bacteria during the enrichment process was studied based on the membrane bioreactor(MBR). Completely autotrophic nitrogen removal over nitrite(CANON) process was started up by constant aeration rate. Simultaneous denitrification of ammonia oxidizing bacteria(AerAOB) and anaerobic ammonia oxidizing bacteria(AnAOB) by optimizing the intermittent aeration and effectively inhibiting the activity of nitrite oxidizing bacteria(NOB), then the simultaneous nitrification, anammox and denitrification(SNAD) process was started up successfully by adding the the carbon source(sodium acetate). The results showed that enhanced the activity of anaerobic ammonia-oxidizing bacteria during the enrichment process of anaerobic ammonia-oxidizing bacteria by continuously shortening the hydraulic retention time(HRT) and increasing influent nitrogen loading. The average activity of the anaerobic ammonia-oxidizing bacteria increased from 0.603 mgN/(h·gVSS) to 8.1 mgN/(h·gVSS). When the constant aeration rate was 50 mL/min and the intermittent aeration(non-aeration time:aeration time, mim/min) was 4:10, the removal of ammonium by AerAOB and AnAOB accounted for 58.8% and 41.2% of the total ammonium removal respectively, and the amount of nitrite nitrogen oxidized by NOB accounted for 15.3% of the total nitrate nitrogen production, successfully inhibiting the activity of NOB. When the C/N ratio was 0.5 and the intermittent aeration was adjusted to 4:15, the nitrogen removal rate in the denitrification process accounted for 20.9% of the total nitrogen removal rate, and the nitrogen removal rate in the anaerobic ammonia oxidation process accounted for 79.1% of the total nitrogen removal rate. The purpose of synergistic denitrification of AerAOB, AnAOB and denitrifying bacteria(DNB) was achieved finally.