连续流反应器污水硝化过程中的N2O释放

污水生物脱氮硝化阶段是温室气体一氧化二氮(N2O)的重要释放源。采用连续流反应器在2种进水氨氮(NH4-N,低氮反应器60 mg/L和高氮反应器180 mg/L)浓度条件下驯化硝化菌,并研究了不同初始NH4-N浓度和不同初始亚硝酸盐(NO2-N)浓度条件下所驯化硝化菌释放N2O的特征。结果表明在反应器运行过程中2个反应器释放N2O较少,均小于去除NH4-N浓度的0.01%;N2O的释放均随着初始NH4-N浓度或初始NO2-N浓度的升高而增加;不同初始NH4-N浓度条件下,低氮反应器驯化硝化菌的N2O释放率在0.51%~1.40%之间,高氮反应器驯化硝化菌在0.29%~1.27%之间;不同初始NO2-N浓度条件下,低氮反应器驯化硝化菌的N2O释放率在1.38%~3.78%之间,高氮反应器驯化硝化菌在1.16-5.81%之间。

N2O emission during nitrification in constant flow biological wastewater treatment systems

Nitrification in biological nitrogen removal from wastewater is a main source of nitrous oxide (N₂O). Two constant flow reactors were operated to enrich nitrifiers with two influent ammonium (NH₄-N) concentrations of 60 mg/L (low-N-reactor) and 180 mg/L (high-N-reactor), and then effects of different initial NH₄-N concentrations and initial nitrite (NO₂-N) concentrations on the N₂O emission for the acclimated nitrifiers were examined. There was not much N₂O emission during the constant operation of the reactors, with the ratio of N₂O emission to the removed NH₄-N less than 0.01%. N₂O emission increased with increasing both initial NH₄-N and NO₂-N concentrations. At different initial NH₄-N concentrations, the ratio of N₂O emission to the removed NH₄-N was in the range from 0.51% to 1.40% for activated sludge from the low-N-reactor and from 0.29% to 1.27% from the high-N-reactor. At different initial NO₂-N concentrations, the ratio of N₂O emission to the removed NH₄-N was in the range from 1.38% to 3.78% for activated sludge from the low-N-reactor and from 1.16% to 5.81% from the high-N-reactor.