SASD-A体系构建及进水不同S/N对脱氮工艺的影响机制

Construction of sulfur autotrophic short-cut denitrification and anaerobic ammonium oxidation(SASD-A)coupling system and effect mechanisms of influent S/N ratio on denitrification process

为了解决低碳或无机类工业废水中硝酸盐和氨氮含量高且难去除的问题,本实验采用厌氧反应器,接种普通厌氧颗粒污泥,以Na2S2O3为电子供体,通过逐渐提升进水NO_(3)^(-)-N浓度的方式快速启动硫自养短程反硝化过程(SASD),然后,在此基础上加载附着厌氧氨氧化(Anammox)菌的填料,控制温度为(30±1)℃,经过147天的运行,构建了硫自养短程反硝化与厌氧氨氧化耦合工艺(SASD-A)。阐明了SASD和Anammox之间的相互作用和脱氮贡献率,探究了进水不同S/N (S2O32-:NO_(3)^(-)-N)浓度比值对(SASD-A)体系脱氮效能的影响机制及微生物种群响应特性。结果表明:不同进水S/N比对SASD-A工艺脱氮性能影响明显,当进水S/N比为3/1时,NH_(4)^(+)-N、NO_(3)^(-)-N和TN的去除率分别为91.49%、90.81%和91.44%。不同S/N对SASD-A耦合体系中功能菌属的相对丰度有着直接的关系,与脱氮功能相关的主要优势菌属有Limnobacter (2.85%~4.71%),Denitratisoma (1.01%~1.99%),Candidatus_Brocadia (2.28%~18.81%),norank_f_Bacteroidetes_vadin HA17 (6.68%~10.81%),norank_f_PHOS-HE36(6.93%~11.47%)等。批次实验表明,在SASD-A体系中,硫氧化菌以还原性Na2S2O3为电子供体,将其转化为S0和硫酸盐,同时将水体中硝酸盐还原为亚硝酸盐,产生的亚硝酸盐和氨氮在有厌氧氨氧化菌的作用下发生反应,生成气态氮,厌氧氨氧化在脱氮过程中占主导地位。

To solve the problem of high nitrate and ammonia nitrogen content and difficult removal in low carbon or inorganic industrial wastewater.The proposed sulfur(thiosulfate)-driven denitrification and anaerobic ammonium oxidation(Anammox)process was developed in two phases:first,the sulfur autotrophic short-cut denitrification(SASD)process was started up by gradually increasing the nitrate concentration in influent,and then,Anammox bacteria were loaded onto the filler,at(30±1)℃,a sulfur autotrophic short-cut denitrification coupled with anammox system(SASD-A)was constructed in 147 days.The interaction between SASD and Anammox process and denitrification contribution rate were clarified.Also,the effect mechanisms and microbial population response characteristics of different S/N(S2O32-∶NO_(3)^(-)-N)ratios on the denitrification efficiency of the coupling process(SASD-A)were discussed.The results showed that the removal efficiencies of NH4+-N,NO_(3)^(-)-N and TN were 91.49%,90.81%and 91.44%respectively,with the S/N of 3/1 in influent.The different S/N had a direct relationship with the relative abundance of functional bacterial genera.The dominant genera associated with denitrification function in the SASD-A system were Limnobacter(2.85%—4.71%),Denitratisoma(1.01%—1.99%),Candidatus_Brocadia(2.28%—18.81%),norank_f_Bacteroidetes_vadinHA17(6.68%—10.81%)and norank_f_PHOS-HE36(6.93%—11.47%)etc.Batch experiments showed that sulfur-oxidizing bacteria used reduced thiosulfate as an electron donor to convert it into S0 and sulfate,and nitrate was reduced to nitrite at the same time.And then it continued to be reduced to nitrogen gas taken ammonia as electron donor in the SASD-A system.Anammox process was responsible for the dominant nitrogen removal in the SASD-A system.