N2O emissions from an intermittently aerated semi-aerobic aged refuse bioreactor: Combined effect of COD and NH4 + -N in influent leachate
N2O emissions from an intermittently aerated semi-aerobic aged refuse bioreactor: Combined effect of COD and NH4 + -N in influent leachate
复制标题
间歇曝气半好氧老化垃圾生物反应器的 N2O 排放：渗滤液进水中 COD 和 NH4-N 的综合影响
DOI：
10.1016/j.wasman.2017.08.022
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发表时间：
2017
期刊：
影响因子：
8.1
通讯作者：
Dalei Zhang
中科院分区：
文献类型：
--
作者：
Weihua Li;Yingjie Sun;Rongxing Bian;Huawei Wang;Dalei Zhang
碳氮比(COD/NH4+-N)是影响污水处理过程中硝化反硝化的重要因素，也是影响氧化亚氮(N2O)排放的重要因素。本研究对两个模拟间歇曝气准好氧老化垃圾生物反应器(SAARB)进行了研究。研究分析了渗滤液处理中进水COD和NH4+-N的差异和组合对N2O排放的影响。实验结果表明，随着进水COD/NH4+-N的降低，N2O排放量增加。在相同进水COD/NH4+-N比(分别为2.7和8.0)下，进水COD对N2O排放的影响大于NH4+-N。最大N2O排放量占进水渗滤液总脱氮量的8.82±22.65%，最大值出现在COD为2000 mg/L时，分析了相同COD/NH4+-N比下进水碳源的差异，认为可生物降解碳基质(即葡萄糖)的有效性是影响N2O排放的重要因素。在较低进水COD/NH4+-N比值(2.7)下，可生物降解碳基质越多，N2O转化率越高。虽然SAARB包括N2O的生成和还原过程，但N2O的还原主要发生在过程的后期，即渗滤液回流后。最大N2O排放速率出现在单周期(24小时)实验的第一个小时，因为渗滤液与地表AR接触。在实际的SAARB应用中，可以通过减少NH4+-N基质的初始回流负荷、添加可生物降解碳基质和/或延长进水渗滤液的水力停留时间(HRT)等措施来减少N2O的排放。
The carbon–nitrogen ratio (COD/NH4+-N) is an important factor affecting nitrification and denitrification in wastewater treatment; this factor also influences nitrous oxide (N2O) emissions. This study investigated two simulated intermittently aerated semi-aerobic aged refuse bioreactors (SAARB) filled with 8-year old aged refuse (AR). The research analyzed how differences in and the combination of influent COD and NH4+-N impact N2O emissions in leachate treatment. Experimental results showed that N2O emissions increased as the influent COD/NH4+-N decreased. The influent COD had a greater effect on N2O emissions than NH4+-N at the same influent ratios of COD/NH4+-N (2.7 and 8.0, respectively). The maximum N2O emission accounted for 8.82 ± 2.65% of the total nitrogen removed from the influent leachate; the maximum level occurred when the COD was 2000 mg/L. An analysis of differences in influent carbon sources at the same COD/NH4+-N ratios concluded that the availability of biodegradable carbon substrates (i.e.glucose) is an important factor affecting N2O emissions. At a low influent COD/NH4+-N ratio (2.7), the N2O conversion rate was greater when there were more biodegradable carbon substrates. Although the SAARB included the N2O generation and reduction processes, N2O reduction mainly occurred later in the process, after leachate recirculation. The maximum N2O emission rate occurred in the first hour of single-period (24 h) experiments, as leachate contacted the surface AR. In practical SAARB applications, N2O emissions may be reduced by measures such as reducing the initial recirculation loading of NH4+-N substrates, adding a later supplement of biodegradable carbon substrates, and/or prolonging hydraulic retention time (HRT) of influent leachate.