搅拌速率对异养反硝化过程N_2O产生过程的影响

Effect of Stirring Velocity on N_2O Production in Heterotrophic Denitrification Process

为揭示搅拌速率对异养反硝化过程N_2O产生过程的影响,选用经全程和短程反硝化序批式反应器驯化的活性污泥,基于N_2O连续监测技术,研究了搅拌速率分别为200、300和400 r/min时不同进水C/N比条件下异养反硝化过程N_2O的产生特征。研究结果表明,搅拌速率变化对全程反硝化过程和短程反硝化过程N_2O产生的影响结果不尽相同。在全程反硝化过程中,N_2O的生成速率和降解速率随着搅拌速率的增加而增加;在短程反硝化过程中,N_2O的生成速率和降解速率不会随着搅拌速率的增加而增加;短程反硝化过程N_2O的产生量和排放量大于全程反硝化过程。在保证混合效果的前提下,异养反硝化过程应在尽可能低的搅拌速率下运行,可以使反硝化过程产生和排放的N_2O量达到最小。

To reveal the effects of stirring velocity on N2O emissions during denitrification process, acclimated activated sludge from denitrification and denitritation sequencing batch reactors were utilized to study the impacts of stirring velocities of 200 r/min, 300 r/min and 400 r/min on N2O production in the heterotrophic denitrification and denitritation with batch tests,and continuously monitoring technology was used to monitor variations of N2O concentrations in the liquid phase. The results indicated that the effects of stirring velocity on the production of N2O in denitrification and denitritation were not the same.During heterotrophic denitrification, the production and consumption rates of N2O were increased with the increasing of stirring velocity; however, during heterotrophic denitritation, the production and consumption rates of N2O were not increased with the increasing of stirring velocity; the amounts of N2O production and emission in the heterotrophic denitritation was higher than those in the heterotrophic denitrificaiton. On the premise of ensuring the mixing effect, the heterotrohphic denitrification process should be operated under a low stirring velocity for minimizing N2O production and emissions.