School of Civil and Architecture Engineering, Northeast Electric Power University, Jilin 132012, China.
School of Civil and Architecture Engineering, Northeast Electric Power University, Jilin 132012, China.
Bioresour Technol. 2019 Nov;291:121809. doi: 10.1016/j.biortech.2019.121809. Epub 2019 Jul 13.
Dissolved oxygen (DO) level is crucial in shaping bacterial community and impacts biological nitrogen removal and nitrous oxide (NO) emission. Online gaseous and off-line dissolved NO under varying DO levels through aeration rate alternations were measured in lab-scale anoxic-oxic reactors. It showed that sharp changes in DO levels caused immediate NO emission increase, while the total average gaseous NO emission stabilized at 0.011%, 0.046%, 0.308% and 0.229% of influent nitrogen as DO in oxic tanks averaged at 0.58, 1.67, 3.2 and 6.12 mg/L, respectively. Process with an average DO concentration of 1.67 mg/L had the highest microbial diversity and relative abundances of potential denitrifers and ammonia-oxidizing bacteria (NOB), while the least ammonia-oxidizing bacteria (AOB) were detected, which contributed to efficient nitrogen removal and minor NO emission. In conclusion, regulation and control of denitrifiers, AOB and NOB with the determination of a proper DO set point is feasible for NO mitigation.
溶解氧（DO）水平对细菌群落的形成至关重要，并影响生物脱氮和氧化亚氮（NO）的排放。通过改变曝气速率，在实验室规模的缺氧-好氧反应器中在线测量了不同 DO 水平下的气态和离线溶解态 NO。结果表明，DO 水平的急剧变化会立即导致 NO 排放增加，而总平均气态 NO 排放稳定在 0.011%、0.046%、0.308%和 0.229%，进水氮分别为好氧池中的 DO 平均值为 0.58、1.67、3.2 和 6.12mg/L。在平均 DO 浓度为 1.67mg/L 的条件下，微生物多样性最高，潜在反硝化菌和氨氧化菌（NOB）的相对丰度最高，而检测到的氨氧化菌（AOB）最少，这有助于高效脱氮和减少 NO 排放。总之，通过确定适当的 DO 设定点来调控反硝化菌、AOB 和 NOB 是可行的，可以减轻 NO 的排放。
