Abstract:The effect of COD/N ratios and pH on N2O production was studied in sequencing batch reactors (SBR). The initial NO2--N concentration of 30mg N/L was obtained by adding NaNO2, the COD/N ratios of 0, 1.5, 3 and 4.5 were reached by adding ethanol, and the pH were controlled at 6, 7, and 8. The experimental results showed that low COD/N produced more N2O with the maximum N2O generating capacity of 2.35mg/L, and low pH conditions increased the accumulation of N2O. The production rate of N2O reached 2.35×10-3mgN/(mgMLSS?L?h) at low COD/N and low pH. There were two reasons. The ability of N2O reductase for competing electrons was weak, and sufficient electron donors were favorable for the reduction of N2O. Low pH affected microbial metabolism, and the N2O reductase were inhibited by HNO2 (produced by H+ and NO2- ). The study showed that sufficient carbon sources and alkaline conditions were the key factors to reduce the accumulation of N2O in nitrite denitrification processes.
李鹏章, 王淑莹, 彭永臻, 刘越. COD/N与pH值对短程硝化反硝化过程中N2O产生的影响[J]. 中国环境科学, 2014, 34(8): 2003-2009.
LI Peng-Zhang, WANG Shu-Ying, PENG Yong-Zhen, LIU Yue. Effect of COD/N ratios and pH on N2O production during nitrite denitrification process. CHINA ENVIRONMENTAL SCIENCECE, 2014, 34(8): 2003-2009.