Impact of COD/N ratio on nitrous oxide emission from microcosm wetlands and their performance in removing nitrogen from wastewater.
Impact of COD/N ratio on nitrous oxide emission from microcosm wetlands and their performance in removing nitrogen from wastewater.
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DOI：
10.1016/j.biortech.2009.01.056
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发表时间：
2009-06
影响因子：
11.4
通讯作者：
Juan Wu;Jian Zhang;W. Jia;H. Xie;R. Gu;Cong Li;B. Gao
中科院分区：
文献类型：
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作者：
Juan Wu;Jian Zhang;W. Jia;H. Xie;R. Gu;Cong Li;B. Gao
人工湿地被认为是一氧化二氮的重要来源。为了研究进水COD/N比对N2O排放的影响，控制脱氮过量排放，利用自由水面微生态湿地，采用不同的进水进行补给。此外，为了更好地了解不同运行COD/N比下N2O的产生机理，还考察了氮素的转化。结果表明，废水进水COD/N比对微观世界湿地的N2O排放和湿地性能有显著影响。N2O产生率与亚硝酸盐之间存在很强的相关性(r=0.421，p<；0.01)。在反硝化过程中，DO浓度对N2O的产生率有重要影响。通过调节外部碳源，获得了最佳的进水COD/N比，从而最有效地控制了N2O的排放，并使水煤浆的脱氮效果达到最佳。结果表明，在COD/N=5的运行条件下，总N2O排放量最小，微型湿地对废水脱氮效果最好。
Constructed wetlands (CWs) are considered to be important sources of nitrous oxide (N2O). In order to investigate the effect of influent COD/N ratio on N2O emission and control excess emission from nitrogen removal, free water surface microcosm wetlands were used and fed with different influent. In addition, the transformation of nitrogen was examined for better understanding of the mechanism of N2O production under different operating COD/N ratios. It was found that N2O emission and the performance of microcosm wetlands were significantly affected by COD/N ratio of wastewater influent. Strong relationships exist between N2O production rate and nitrite (r=0.421, p<0.01). During denitrification process, DO concentration crucially influences N2O production rate. An optimal influent COD/N ratio was obtained by adjusting external carbon sources for most effective N2O emission control and best performance of the CWs in nitrogen removal from wastewater. It is concluded that under the operating condition of COD/N ratio=5, total N2O emission is minimum and the microcosm wetland is most effective in wastewater nitrogen removal.