废水生物脱氮过程中N_(2)O排放数学模型研究进展

RECENT ADVANCES IN MATHEMATICAL MODELING OF NITROUS OXIDES EMISSION DURING BIOLOGICAL NITROGEN REMOVAL FROM WASTEWATER

氧化亚氮(N_(2)O)的温室效应比CO_(2)强265倍,可从废水生物脱氮过程中产生并直接排放,如果不对其加以控制,会显著增加污水处理厂的碳足迹。N_(2)O排放的数学建模对于深入解析N_(2)O产生机制、量化N_(2)O排放、优化生物脱氮工艺和制定N_(2)O减排策略具有重要意义。结合当前国内外研究现状,阐述了废水生物脱氮过程中N_(2)O产生机制;归纳了基于不同机制建立的N_(2)O数学模型,包括氨氧化细菌(ammonia-oxidizing bacteria,AOB)经过羟胺氧化途径和AOB反硝化途径产生N_(2)O模型、异养反硝化途径产生N_(2)O模型以及耦合AOB和异养反硝化细菌产生N_(2)O模型;总结了新型生物脱氮系统N_(2)O模型,实际工程应用情况及校准N_(2)O数学模型中存在的问题;并对今后N_(2)O数学模型的研究方向进行了展望。

Nitrous oxide(N_(2)O) is a greenhouse gas with an approximately 265-fold stronger warming effect than carbon dioxide.N_(2)O can be produced and directly emitted during biological nitrogen removal from wastewater.The carbon footprint from wastewater treatment plants may be significantly increased if N_(2)O production and emissions are not controlled.Mathematical modeling of N_(2)O emissions is of great importance for the in-depth clarification of N_(2)O production mechanisms,the quantification of N_(2)O emissions,the optimization of biological nitrogen removal,and the development of mitigation strategies.Combing with the state of the art,the production mechanisms of N_(2)O were described.N_(2)O mathematical models based on different mechanisms were concluded,including the ones predicting N_(2)O production by ammonia-oxidizing bacteria(AOB)through the hydroxylamine oxidation pathway and the AOB denitrification pathway,by heterotrophic denitrifiers through the denitrification pathway and by both groups of microbes through the integration of these pathways.The models of N_(2)O emissions in advanced nitrogen removal processes,practical engineering application of N_(2)O models,and the existing problems in model calibration were summarized in detail,and the future research directions of N_(2)O modeling were prospected.