不同污水生物脱氮工艺中N2O释放量及影响因素

微生物的硝化及反硝化过程为污水处理过程中N2O的主要产生源.从微生物学和生物化学反应的角度,阐述了硝化及反硝化过程中N2O的生成机理以及与N2O产生相关的关键酶的基本特性,同时给出了几种典型硝化及反硝化菌的N2O产生与释放情况.通过对实际污水处理厂、不同污水处理工艺,尤其是新工艺过程中N2O释放量及产因的分析,指出污水生物处理过程中N2O的释放量与污水水质、污水处理工艺、工艺的运行工况及微生物的种群结构有关,并对底物浓度、DO浓度、SRT等关键性因素进行了重点论述.在综合分析N2O产生机理及影响因素的基础上,从工艺运行工况及微生物种群优化2个角度,初步提出了控制污水生物处理过程中N2O释放的策略.

N2O emissions from different biological nitrogen removal processes and factors affecting N2O production

Microbiological nitrification and denitrification were considered to be the major sources of N2O in wastewater treatment processes. The microbiological mechanism of N2O production in nitrification and denitrification and the basic characteristics of key enzymes related to N2O production were illustrated. In addition, the N2O production of several typical nitrifiers and denitrifiers was summarized. Through analyzing N2O emissions from wastewater treatment plants and different wastewater treatment processes, especially novel wastewater treatment processes, it was concluded that N2O emissions were affected by wastewater characteristics, treatment processes, operating conditions and the structures of microbial communities. Moroover, main factors affecting N2O production were reviewed, including substrate concentration, DO concentration and SRT. Finally, the preliminary strategies for controlling N2O emission from wastewater treatment process were put forward on the basis of synthetically analysis of microbiological mechanism and factors affecting N2O production.