不同电子受体反硝化过程中C/N对N_2O产量的影响  

Effect of C/N Ratio on Nitrous Oxide Production During Denitrification with Different Electron Acceptors

作　　者：尚会来[1] 彭永臻[1] 张静蓉[1] 王淑莹[1] 

机构地区：[1]北京工业大学北京市水质科学与水环境恢复工程重点实验室,北京100124

出　　处：《环境科学》2009年第7期2007-2012,共6页Environmental Science

基　　金："十一五"国家科技支撑计划重点项目(2006BAC19B03);北京市教委科技创新平台项目(PXM2008-014204-050843);北京工业大学研究生科技基金项目(ykj-2007-1063)

摘　　要：试验采用SBR反应器,分别考察了不同C/N条件下,以硝酸盐和亚硝酸盐为电子受体的反硝化过程中N2O产生情况.投加乙醇作为反硝化碳源,以硝酸盐为电子受体时调节C/N分别为0、1.2、2.4、3.5、5.0和20,以亚硝酸盐为电子受体时调节C/N分别为0、1.8、2.4、3.0、4.3、5.2、6.6和20.6.结果发现,以亚硝酸盐为电子受体时,最佳C/N为3.0,此时N2O产生量为0.044mg·L-1;以硝酸盐为电子受体时,最佳C/N为5.0,此时N2O产生量为0.135mg·L-1,是以亚硝酸盐为电子受体时的3倍.电子受体类型不同时,N2O产生量的变化趋势类似:在碳源严重不足时,反硝化率和N2O产生量均很低;碳源相对不足时N2O产生量增加;C/N过大时,虽然反硝化速率很快,但N2O产量也急剧增大.可见,与全程硝化反硝化工艺相比,短程硝化反硝化工艺可节省40%碳源,且控制C/N=3,其反硝化过程产生的N2O远少于全程反硝化.The experiment investigated the nitrous oxide production under different C/N ratios during denitrification, taking nitrate and nitrite as electron acceptor respectively. Ethanol was selected as carbon source. The C/N ratios were 0, 1.2, 2.4, 3.5, 5.0 and 20 when nitrate was taken as electron acceptor and C/N ratios 0, 1.8, 2.4, 3.0, 4.3, 5.2, 6.6, 20.6 when electron acceptor was nitrite. The results indicated that： the optimum C/N ratio was 3.0 taking nitrite as electron acceptor and the N2O production was 0.044 mg· L^-1 ; the optimum C/N ratio was 5.0 taking nitrate as electron acceptor and the N2O production was 0.135 mg·L^-1 which was 3 times higher than that of nitrite as electron acceptor. Though the electron acceptor changed, the trend of N2O production was similar： when carbon source was badly insufficient, the production of N2O and denitrification rate were both quite small; the N2O production increased with the increasing of the quantity of carbon source; when the carbon source was excessive, the N2O production sharply raised. Consequently, compared to complete nitrification and denitrification, short-cut nitrification and denitrification could save 40% carbon source. Moreover, controlling C/N = 3 could reduce the production of N2O in short-cut nitrification.

关 键 词：反硝化 硝酸盐 亚硝酸盐 C/N 氧化亚氮 

分 类 号：X703.1[环境科学与工程—环境工程]