城市污水A^2/O处理系统好氧池N2O和NO的释放特征及影响因素

The emission characteristics of nitrous oxide and nitric oxide and related influence factors in an aeration tank of amunicipal wastewater treatment plant using an A^2/O process

以某污水处理厂好氧曝气池为研究对象,利用N_2O和NO在线检测仪,监测好氧池不同空间位置处N_2O和NO的释放量,考察了氮素浓度、溶解氧及p H值对N_2O和NO释放量的影响.该污水处理厂好氧池DO浓度在0.24~1.12mg/L之间,且大多处于0.6mg/L左右,较低的DO导致NO2--N浓度沿水流推流方向不断积累;相应的,N_2O和NO释放量沿水流推流方向不断升高,并于好氧池末段达到最高值.NO释放NO2--N量与浓度显著正相关,N_2O释放量与NO2--N浓度也有一定的相关性,但没有NO显著.基于空间检测数据估算获得该污水处理厂N_2O释放量占进水NH_4+-N比例为6.34%~8.83%,NO释放量占进水NH4+-N比例为0.033%~0.034%.

In this study, online N2O and NO analyzer were used to monitor N2O and NO emissions in different zones of the aeration tank of a municipal wastewater treatment plant. Parameters such as ammonia, nitrite, nitrate, dissolved oxygen（DO） and p H were also measured to reveal their influence on N2O and NO emissions. The results showed that the DO concentration of the aeration tank was between 0.24mg/L and 1.12mg/L, and mostly at approximately 0.6mg/L. The low DO concentration led to the nitrite accumulation along the aeration tank. The N2O and NO emission rose along the aerobic tank and ultimately reached the maximum value at the end of the aeration tank. Besides, NO emission was significantly and positively correlated with the nitrite concentration, while the N2O emission was less significant. The N2O and NO emission factors of the wastewater treatment plant were 6.3-8.83% and 0.033-0.034% of influent ammonia.