好氧颗粒污泥短程硝化处理养殖废水及N_2O释放特性

Characteristics of Partial Nitrification and N_2O Emissions Through Aerobic Granular Sludge Treating Livestock Wastewater

好氧颗粒污泥可通过特殊的厌/好氧空间结构实现短程硝化,而短程硝化和好氧颗粒结构都可能导致温室气体N_2O释放.试验研究了处理养殖废水过程中好氧颗粒污泥短程硝化性能,及利用微电极探针定量分析N_2O过程释放特性.稳定运行期间,COD与氨氮平均去除率分别为76.8%和94.4%,短程硝化效率可达88.9%.根据微电极探针和气相色谱分析结果,好氧颗粒污泥系统厌氧和好氧阶段N_2O生成量分别占46.4%和53.6%,但短程硝化系统的N_2O释放主要来源于曝气吹脱作用;系统内N_2O中氮的释放量占进水氮的比例为2.1%,好氧颗粒污泥并未显著强化N_2O释放.

Aerobic granular sludge can achieve partial nitrification due to the special anaerobic/ aerobic space structure. However,the greenhouse gas N2O could emit through partial nitrification and aerobic granular structure. In this study,performance of partial nitrification in an aerobic granular sludge reactor treating livestock wastewater was investigated, and its characteristics of N2O emissions were quantified by sensitive N2O micro- sensors. In the steady-state,the average COD and ammonium removal rates were 76.8 % and 94.4%, respectively. The partial nitrification efficiency reached 88.9 % . According to the results of micro-sensors and gas chromatography,the proportion of N2O generation from anaerobic and aerobic stage in the aerobic granular sludge system was 46. 4% and 5 3 . 6 %,respectively,but the N2O emissions from the partial nitrification system were mainly caused by air stripping in aeration phase. The ratio of N2O - N emissions was 2.1% of the influent nitrogen loading from this system. It showed N2O emissions were not significantly enhanced by the aerobic granular sludge.