CAJ | 학술논문

N2O是一种强效的温室气体，而污水生物脱氮过程是N2O产生的一个主要人为来源。在本研究中，向生物处理出水中投加NH+4、NH2OH及NO?2，研究了NO?2对NH+4及NH2OH氧化过程中N2O产生的影响。试验结果表明，NH+4及NH2OH氧化过程的最初30 min内（总反应时间180 min）产生的N2O占总N2O产生量的25%以上。在NH4+或NH2OH氧化完成前的30 min内，N2O的净产生量仅有0.2 mg·L?1。NH2OH的氧化是短程硝化开始阶段产生N2O的途径，此后NH+4或NH2OH氧化为AOB提供还原NO?2电子，引起的反硝化作用是产生N2O的主要途径。在实际生活污水短程硝化试验过程中，由于部分 COD 的存在，在低氧条件下，可能会出现异养菌的反硝化作用。同时，由于氧气及NO?2对氧化亚氮还原酶（NOS）的抑制，使得在生活污水进行短程硝化时，N2O的净产量比上述出水试验时增加了17%以上，总产量最高达到了11.07 mg·L?1。这一途径对N2O产生的贡献也是不容忽视的。
N2O시일충강효적온실기체，이오수생물탈담과정시N2O산생적일개주요인위래원。재본연구중，향생물처리출수중투가NH+4、NH2OH급NO?2，연구료NO?2대NH+4급NH2OH양화과정중N2O산생적영향。시험결과표명，NH+4급NH2OH양화과정적최초30 min내（총반응시간180 min）산생적N2O점총N2O산생량적25%이상。재NH4+혹NH2OH양화완성전적30 min내，N2O적정산생량부유0.2 mg·L?1。NH2OH적양화시단정초화개시계단산생N2O적도경，차후NH+4혹NH2OH양화위AOB제공환원NO?2전자，인기적반초화작용시산생N2O적주요도경。재실제생활오수단정초화시험과정중，유우부분 COD 적존재，재저양조건하，가능회출현이양균적반초화작용。동시，유우양기급NO?2대양화아담환원매（NOS）적억제，사득재생활오수진행단정초화시，N2O적정산량비상술출수시험시증가료17%이상，총산량최고체도료11.07 mg·L?1。저일도경대N2O산생적공헌야시불용홀시적。
Nitrous oxide (N2O) is one of the most important greenhouse gases, about 265 times stronger than carbon dioxide (CO2), and it may also destroy the ozone layer. In the biological wastewater treatment process, autotrophic nitrification has been thought to be the major source of N2O production. So it becomes increasingly important to prevent N2O emission from sewage treatment. In this study, by adding NH+4, NH2OH and NO?2 to the effluent, the effect of NO?2 on N2O production by NH+4 and NH2OH oxidation during the nitritation process was investigated in a laboratory batch-scale system with activated sludge for treating domestic wastewater. Within the first 30 min of NH+4 and NH2OH oxidation process (total test time:180 min) N2O accounted for more than 25%of the total production. As NH+4 or NH2OH was consumed completely, the amount of N2O net production reduced to less than 0.2 mg·L?1 in the last 30 min. Furthermore, the concentration of NO?2-N could affect N2O production.The increase of NO?2-N would promote generation of N2O. The maximum total N2O net production was 6.86 mg·L?1 when the concentration of NO?2 was 60 mg·L?1. NH2OH oxidation played a key role in N2O production at the very beginning of the experiment while nitrifier denitrification became a main pathway later. When the domestic sewage was treated under DO limited conditions, due to the presence of COD, there might occur heterotrophic denitrification during the aeration phase. However, oxygen and NO?2 had strong inhibition on the activity of nitrous oxide reductase (NOS), consequently N2O could not be reduced to N2 completely. It led to more than 17% N2O was produced and the maximum total net production reached 11.07 mg·L-1. Hence, the contribution to N2O produced by denitrification could not be ignored during the domestic wastewater treatment. Besides co-existence of NH+4 and NH2OH could significantly increase N2O production and this process also emitted more N2O when the concentration of NO?2 was increased.