Evaluation of nitrogen removal and N2O emission in a novel anammox coupled with sulfite-driven autotrophic denitrification system: Influence of pH

JOURNAL OF CLEANER PRODUCTION

卷:321

Article

Cao, Xiwei^1,2  Zhou, Xin^1,2  Xue, Mi^1,2  Chen, Jiabo^1,2  Li, Shuhan^1,2 

[1] Taiyuan Univ Technol, Coll Environm Sci & Engn, Taiyuan 030024, Peoples R China

[2] Innovat Ctr Postgrad Educ Municipal Engn Shanxi P, Taiyuan 030024, Peoples R China

关键词: Anammox;    Sulfite-driven autotrophic denitrification;    Nitrogen removal;    N2O emission;    pH;    Microbial community;   

DOI  :  10.1016/j.jclepro.2021.128984

来源: Elsevier

【 摘 要 】

A combination of anaerobic ammonium oxidation (anammox) with sulfur-autotrophic denitrification is a promising alternative for complete nitrogen removal. Herein, a novel anammox coupled with sulfite-driven autotrophic denitrification (ASDAD) is firstly proposed. The influence of pH (8.5-6.5) on nitrogen removal and N2O emission is investigated in an anaerobic sequencing batch biofilm reactor fed with low-nitrogen wastewater containing sulfite. Long-term operation demonstrates that a maximum nitrogen removal of 94.5% occurred at a pH of 7.5 and that the contribution of autotrophic denitrification to nitrogen removal increased as the pH declined. Cyclic and batch experiments verify that anammox and sulfite-autotrophic denitrification simultaneously participates in nitrogen removal, and the stoichiometry for sulfite-driven autotrophic denitrification is firstly proposed. Furthermore, N2O accumulation is also highly correlated with the pH. The N2O emission peaks at a pH of 6.5 due to the inactivated anammox and incomplete autotrophic denitrification of nitrite at such a low pH. High-throughput sequencing reveals the coexistence of anammox (Candidatus Brocadia and Candidatus Kuenenia) and sulfur-oxidizing species (Thiobacillus). Finally, the schema for nitrogen conversion and N2O formation of ASDAD is elucidated based on metagenomic metabolism. This study offers a cost-effective and environment-friendly completely autotrophic nitrogen removal process for municipal wastewater with a low carbon-to-nitrogen ratio in practice.

【 授权许可】

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