污水生物脱氮反硝化过程N_2O的释放影响研究

针对污水反硝化处理过程中N_2O释放不明确的问题,在序批式反应器中探究了不同电子受体及初始碳源浓度对N_2O的释放影响并探究相应机理。结果表明以乙醇为电子供体时,NO_3~--N作为电子受体能够减少N_2O的释放,N_2O的最大释放量仅为0.061 mg/L,是NO_2~--N为电子受体的0.1倍。N_2O为电子受体能够抑制N_2O的还原酶活性。当乙醇的初始浓度由50 mg/L增加至150 mg/L时,反应过程中未出现NO_2~--N的积累,但反硝化过程得到强化,NO_3~--N的浓度由40 mg/L下降至15 mg/L,N_2O的释放量由0.61 mg/L下降至0.32 mg/L。机理研究表明乙醇浓度提高减少N_2O释放的主要原因在于强化反硝化过程。

Nitrous Oxide Release from Sewage Biological Denitrification and Denitrification

In view of the unclear N2O emission during the denitrification process of wastewater,the effects of different elec-tron acceptors and initial carbon source concentration on N2O release were explored in sequencing batch reactor and the corre-sponding mechanisms were explored. The results showed that when ethanol was used as electron donor,NO-3-N as the electron acceptor can reduce the release of N2O. The maximum release of N2O was 0.061 mg/L,only 0.1 times that of NO-2-N as the electron acceptor. NO-2-N as an electron acceptor can inhibit N2O reductase activity. When the initial ethanol concentration in-creased from 50 mg/L to 150 mg/L,NO-2N accumulation did not occur during the reaction, but the denitrification process was enhanced. The concentration of NO-3-N decreased from 40 mg/L to 15 mg/L, the N2O release decreased from 0.61 mg/L to 0.32 mg/L. Mechanism studies showed that the main reason for the increase of ethanol concentration to reduce N2O release was the enhanced denitrification process.