Sun Shanshan, Gu Xushun, Zhang Manping, Tang Li, He Shengbing
School of Environmental Science and Engineering, Shanghai Jiaotong University, Shanghai 200240, PR China.
Shanghai Engineering Research Center of Landscape Water Environment, Shanghai 200031, PR China; Shanghai Landscape Architecture Design Institute , Shanghai 200031, PR China.
Bioresour Technol. 2021 Jul;332:125083. doi: 10.1016/j.biortech.2021.125083. Epub 2021 Mar 30.
Electron donors have been widely used to improve denitrification performance. However, it is controversial which electron donor could be chosen. In this study, three electron donors were used to improve nitrogen removal from ecological floating beds (EFBs). The results showed that TN removal efficiency was 49-80%, 46-81%, and 45-79% in EFB-C (sodium acetate), EFB-S (sodium thiosulfate), EFB-Fe (iron scraps), respectively. Nitrification was limited in EFB-C and EFB-S while denitrification in EFB-Fe. The TN removal in the three EFBs were almost equivalent when HRT was 3 days. Lowest CH and NO emissions were measured in EFB-Fe. Nitrifying and denitrifying bacteria were mainly concentrated in the root rhizospheres while iron cycle related and anammox bacteria were mainly concentrated on iron scraps surface. Heterotrophic denitrification and autotrophic denitrification were mainly attributed to TN removal in EFB-C and EFB-S, respectively. Autotrophic, heterotrophic denitrification and anammox contributed to TN removal in EFB-Fe.
电子供体已被广泛用于提高反硝化性能。然而，选择哪种电子供体存在争议。在本研究中，使用了三种电子供体来提高生态浮床（EFBs）的脱氮效果。结果表明，EFB-C（醋酸钠）、EFB-S（硫代硫酸钠）、EFB-Fe（铁屑）中总氮（TN）的去除效率分别为49 - 80%、46 - 81%和45 - 79%。EFB-C和EFB-S中硝化作用受到限制，而EFB-Fe中以反硝化作用为主。当水力停留时间（HRT）为3天时，三种EFBs中的TN去除效果几乎相当。EFB-Fe中测得的CH和NO排放量最低。硝化和反硝化细菌主要集中在根系根际，而与铁循环相关的细菌和厌氧氨氧化细菌主要集中在铁屑表面。EFB-C和EFB-S中TN的去除主要分别归因于异养反硝化和自养反硝化。EFB-Fe中TN的去除则是自养、异养反硝化和厌氧氨氧化共同作用的结果。
