Ren Yangang, Wang Jinhe, Xu Li, Liu Cui, Zong Ruiqiang, Yu Jianlin, Liang Shuang
Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Jinan, People's Republic of China.
Environ Sci Pollut Res Int. 2015 Jun;22(11):8163-73. doi: 10.1007/s11356-015-4408-8. Epub 2015 Apr 8.
Direct emissions of N2O, CO2, and CH4, three important greenhouse gases (GHGs), from biological sewage treatment process have attracted increasing attention worldwide, due to the increasing concern about climate change. Despite the tremendous efforts devoted to understanding GHG emission from biological sewage treatment process, the impact of influent C/N ratios, in terms of chemical oxygen demand (COD)/total nitrogen (TN), on an anaerobic/anoxic/oxic (A/A/O) bioreactor system has not been investigated. In this work, the direct GHG emission from A/A/O bioreactor systems fed with actual sewage was analyzed under different influent C/N ratios over a 6-month period. The results showed that the variation in influent carbon (160 to 500 mg/L) and nitrogen load (35 to 95 mg/L) dramatically influenced pollutant removal efficiency and GHG production from this process. In the A/A/O bioreactor systems, the GHG production increased from 26-39 to 112-173 g CO2-equivalent as influent C/N ratios decreased from 10.3/10.7 to 3.5/3.8. Taking consideration of pollutant removal efficiency and direct biogenic GHG (N2O, CO2, and CH4) production, the optimum influent C/N ratio was determined to be 7.1/7.5, at which a relatively high pollutant removal efficiency and meanwhile a low level of GHG production (30.4 g CO2-equivalent) can be achieved. Besides, mechanical aeration turned out to be the most significant factor influencing GHG emission from the A/A/O bioreactor systems.
由于对气候变化的日益关注，生物污水处理过程中一氧化二氮（N2O）、二氧化碳（CO2）和甲烷（CH4）这三种重要温室气体的直接排放已引起全球越来越多的关注。尽管人们为了解生物污水处理过程中的温室气体排放付出了巨大努力，但进水碳氮比（以化学需氧量（COD）/总氮（TN）计）对厌氧/缺氧/好氧（A/A/O）生物反应器系统的影响尚未得到研究。在这项工作中，分析了在6个月的时间里，不同进水碳氮比条件下，以实际污水为进水的A/A/O生物反应器系统的直接温室气体排放情况。结果表明，进水碳（160至500毫克/升）和氮负荷（35至95毫克/升）的变化极大地影响了该过程的污染物去除效率和温室气体产生量。在A/A/O生物反应器系统中，随着进水碳氮比从10.3/10.7降至3.5/3.8，温室气体产生量从26 - 39克二氧化碳当量增加到112 - 173克二氧化碳当量。综合考虑污染物去除效率和直接生物源温室气体（N2O、CO2和CH4）的产生量，确定最佳进水碳氮比为7.1/7.5，在此条件下可实现相对较高的污染物去除效率，同时温室气体产生量较低（30.4克二氧化碳当量）。此外，机械曝气被证明是影响A/A/O生物反应器系统温室气体排放的最重要因素。
