School of Civil and Architecture Engineering, Northeast Electric Power University, Jilin 132012, China.
Weihai Water Group Co. LTD, Weihai 264200, China; School of Chemical Engineering, Northeast Electric Power University, Jilin 132012, China.
Bioresour Technol. 2021 May;328:124844. doi: 10.1016/j.biortech.2021.124844. Epub 2021 Feb 12.
This study focused on the nitrous oxide (NO) generation from the biological nitrogen removal process under different pH levels. To explore a pH optimum, the online NO emission and the bacterial composition and function in the anoxic-oxic process were investigated. The mean gaseous NO emission accounted for 0.329%, 0.103%, 0.085%, and 0.793% of the influent total nitrogen at pH of 5, 6, 8, and 9, respectively. Incomplete oxidation in oxic tanks was the primary source of NO, while NO in the anoxic tank was mainly generated by nitrifier denitrification. No direct correlations were observed between NO emission and potential nitrifiers and denitrifiers. The impacts of pH on NO generation were more likely related to the response of bacterial enzymes and nitrogen compounds, rather than the feedback of bacterial community structure itself. Above all, an influent pH range of 6-8 is recommended for nitrogen removal and NO mitigation in anoxic-oxic process.
本研究聚焦于不同 pH 值条件下生物脱氮过程中一氧化二氮（NO）的生成。为了探究 pH 值的最佳范围，考察了缺氧-好氧过程中在线 NO 排放以及细菌组成和功能。在 pH 值为 5、6、8 和 9 时，气态 NO 排放分别占进水总氮的 0.329%、0.103%、0.085%和 0.793%。好氧池中的不完全氧化是 NO 的主要来源，而缺氧池中的 NO 主要由硝化菌反硝化生成。NO 排放与潜在硝化菌和反硝化菌之间没有直接相关性。pH 值对 NO 生成的影响可能更与细菌酶和氮化合物的反应有关，而不是与细菌群落结构本身的反馈有关。综上所述，建议在缺氧-好氧工艺中，进水的 pH 值范围为 6-8，以实现脱氮和减少 NO。
