Abstract：
Intermittent hydroxylamine (NH2OH) dosing strategy was applied to enhance the stability of partial nitrification and total nitrogen (N) removal efficiency (TNRE) in a continuous-flow process. The results showed 2 mg/L of NH2OH dosing (once every 6 h) could maintain stably partial nitrification with nitrite accumulation rate (NAR) of 91.6 % and TNRE of 92.6 %. The typical cycle suggested NH2OH dosing could promote simultaneous nitrification-denitrification (SND) and endogenous denitrification (END) while inhibit exogenous denitrification (EXD). Nitrification characteristics indicated the NH2OH dosing enhanced stability of partial nitrification by suppressing specific nitrite oxidation rate (SNOR), Nitrospira and nitrite oxidoreductase enzyme (Nxr). The microbial community suggested the aerobic denitrfiers, denitrifying glycogen accumulating organisms (DGAOs) and traditional denitrfiers were the potential contributor for advanced N removal. Moreover, NH2OH dosage was positively associated with NAR, SND and END. Overall, this study offers a feasible strategy to maintain sustainably partial nitrification that has great application potential.
摘要：
采用间歇性羟胺（NH2OH）投加策略，以提高连续流程中部分硝化和总氮（N）去除效率（TNRE）的稳定性。结果表明，2mg/L的NH2OH投加（每6h一次）可以稳定地维持部分硝化，亚硝酸盐累积率（NAR）为91.6％，TNRE为92.6％。典型循环表明，NH2OH投加可以促进同步硝化反硝化（SND）和内源性反硝化（END），同时抑制外源性反硝化（EXD）。硝化特性表明，NH2OH剂量通过抑制特定的亚硝酸盐氧化速率（SNOR）增强了部分硝化的稳定性，硝基螺旋体和亚硝酸盐氧化还原酶（Nxr）。微生物群落建议使用好氧脱硝剂，反硝化糖原积累生物（DGAOs）和传统脱硝剂是高级N去除的潜在贡献者。此外，NH2OH剂量与NAR呈正相关，SND和END。总的来说,这项研究提供了一个可行的策略，以维持可持续的部分硝化，具有巨大的应用潜力。
