利用羟胺实现城市污水短程硝化最优投加点选择

模拟缺氧/好氧（A/O）模式运行的序批式活性污泥法（SBR）处理系统，探究利用羟胺实现城市污水短程硝化的投加点优化.批次实验发现，溶解氧存在会降低羟胺对亚硝酸盐氧化菌（NOB）抑制效果的（20±0.5）%.此外，相较于未经缺氧处理和延长缺氧时间（>15min）处理，缺氧时间为1~5min可提高NOB活性抑制率13%~25%.长期试验表明，在缺氧段末投加羟胺的短程硝化系统维持NO₂^--N积累率92%以上，而在好氧阶段投加羟胺的系统NO₂^--N积累率逐渐降低.qPCR分析证明，羟胺投加点为缺氧段末可在充分抑制NOB基础上，降低对氨氧化菌（AOB）的抑制作用，从而有利于AOB成为优势菌群结构.本研究为优化羟胺投加点和稳定维持短程硝化提供理论基础.

Selection of optimal dosing point for partial nitrification of municipal wastewater by hydroxylamine

In this study, a sequencing batch reactor (SBR) treatment system operating in anoxic/aerobic (A/O) mode was established, and the optimization of hydroxylamine dosing point on partial nitrification of municipal wastewater was explored. Results of batch experiments showed that the presence of dissolved oxygen could reduce the inhibitory effect of hydroxylamine on NOB by (20±0.5)%. In addition, compared with the treatment without anoxic condition and extended anoxic duration (>15min), the activity inhibited ratio of NOB increased by 13%~25% with anoxic duration of 1~5min. The long-term experiments showed that the NO₂^--N accumulation rate of the partial nitrification system with hydroxylamine addition at the end of anoxic stage maintained above 92%, while it decreased gradually with hydroxylamine at aerobic stage. QPCR analysis showed that the inhibition on ammonia oxidizing bacteria (AOB) could be reduced with sufficient inhibition on NOB when the hydroxylamine was added at the end of anoxic period, facilitating the dominance of AOB in microbial community structure. This study provides a theoretical basis for optimizing hydroxylamine dosing point and maintaining stable partial nitrification process.