锰氧化物介导自养脱氮的启动、效能及机制

Manganese Oxide Mediated Autotrophic Denitrification:Startup,Efficiency and Mechanisms

锰氧化物在厌氧条件下介导自养脱氮是一种很有前途的氨氮废水处理方法。通过调整pH、添加微量元素(EDTA和Fe^(2+))、采用低氨氮负荷的方式启动厌氧反应器,探究锰氧化物介导自养脱氮过程,分析微生物在脱氮过程中的作用。启动成功后,反应器的氨氮去除负荷(ARR)和总氮去除负荷(NRR)分别为(0.031±0.009)、(0.025±0.010)kg(/m^(3)·d),且投加EDTA和Fe^(2+)促进了氨氮的去除。随着颗粒污泥的形成,锰氧化物逐渐由Mn(Ⅳ)向Mn(Ⅱ)转化,又经锰自养反硝化(NDMO)过程形成复杂的生物锰氧化物。反应器内存在多种脱氮菌群,包含锰氧化还原菌群Acinetobacter、Bacillus、Anaeromyxobacter和Geothrix,厌氧氨氧化菌Candidatus_Brocadia以及硝化-反硝化菌群Ellin6067、Nitrospira、norank_f__PHOS-HE36、Nitrosomonas和Denitratisoma。锰氧化物丰富了微生物的多样性,产生了多种脱氮途径。

Manganese oxide mediated autotrophic denitrification is a promising method for treating ammonia wastewater under anaerobic conditions.The anaerobic reactor was activated by adjusting pH,adding trace elements(EDTA and Fe^(2+)),and reducing ammonia nitrogen load.The manganese oxide mediated autotrophic denitrification process and the role of microorganisms was analyzed.It was found that the ammonia nitrogen removal load(ARR)and total nitrogen removal load(NRR)of the reactor were(0.031±0.009)kg/(m^(3)·d)and(0.025±0.010)kg/(m^(3)·d)respectively after successful startup,and the addition of EDTA and Fe^(2+)promoted the conversion of ammonia nitrogen.As the granular sludge formed,manganese oxides gradually transform from Mn(Ⅳ)to Mn(Ⅱ),and then formed complex biological manganese oxides through the manganese autotrophic denitrification process(NDMO).There were various bacterial communities in the reactor,including manganese redox bacteria such as Acinetobacter,Bacillus,Anaeromyxobacter and Geothrix,Anammox bacteria(Candidatus_Brocadia),and the nitrification-denitrification microbial communities Ellin6067,Nitrospira,norank_f__PHOS‑HE36,Nitrosomonas and Denitratisoma.Manganese oxide enriches the diversity of microorganisms and generates multiple denitrification pathways.