生活污水不同生物脱氮过程中N_2O产量及控制  

Formation of N_2O in various biological nitrogen removal processes for treatment of domestic sewage

作　　者：巩有奎[1] 王赛[1] 彭永臻[1] 王淑莹[1] 

机构地区：[1]北京工业大学环境与能源工程学院,北京100022

出　　处：《化工学报》2010年第5期1286-1292,共7页CIESC Journal

基　　金：'十一五'国家科技支撑计划重点项目--村镇分散型污水处理关键设备研制与示范~~

摘　　要：利用好氧-缺氧SBR反应器和全程曝气SBBR反应器处理生活污水,分别实现了全程、短程和同步硝化反硝化脱氮过程,研究了不同脱氮过程中N2O的产生及释放情况,同时考察了不同DO条件下同步脱氮效率及N2O产生量。结果表明,全程、短程生物脱氮过程中N2O主要产生于硝化过程,反硝化过程有利于降低系统N2O产量。全程、短程、同步硝化反硝化脱氮过程中N2O产量分别为4.67、6.48和0.35mg.L-1。硝化过程中NO2-N的积累是导致系统N2O产生的主要原因。部分AOB在限氧条件下以NH4+-N作为电子供体,NO2-N作为电子受体进行反硝化,最终产物是N2O。不同DO条件下同步硝化反硝化过程中N2O的产生表明:控制SBBR系统中DO浓度达到稳定的同步脱氮效率可使系统N2O产量最低。The formation and emission of N2O in various nitrogen removal processes for treatment of domestic sewage were investigated using oxic-anoxic SBR systems and a continuum aerobic submerged biofilm reactor system SBBR,from which complete,shortcut and simultaneous nitrification and denitrification（SND） processes were realized,respectively.Meanwhile,the effect of DO on the SND efficiency and N2O yield in SBBR was also studied.The results showed that for both complete and shortcut N removal processes the formation of N2O was in nitrification process,while denitrification one was favorable for decrease of N2O emission.N2O yield was 4.67 mg·L-1,6.48 mg·L-1 and 0.35 mg·L-1 for complete,shortcut and simultaneous nitrification-denitrification processes,respectively.The main reason for the formation of N2O was the accumulation of NO-2-N during N removal process.A part of AOB could be denitrified between NH＋4-N as electron donor and NO-2-N as electron acceptor under low DO level,which led to the formation of N2O finally.The formation of N2O in simultaneous nitrification and denitrification process at various DO conditions showed that in SBBR system,the minimun N2O yield could be achieved by the control of DO concentration and the efficiency balance of nitrogen removal in both nitrification and denitrification processes.

关 键 词：N2O产量 生活污水 全程硝化反硝化 短程硝化反硝化 同步硝化反硝化 

分 类 号：X703[环境科学与工程—环境工程]