城市污水自养/异养脱氮处理新工艺及其协同竞争机制

Achieving stable and energy-saving nitrogen removal is an important onward direction for municipal wastewater treatment processes. The new Partial Nitritation + simultaneous Anammox/Denitrification and Sludge Fermentation process (PN+ADSF) was proposed by the applicant. Since autotrophic/heterotrophic biochemical processes are combined in the ADSF system, not only stable but also energy-saving nitrogen removal could be expected to realize. However, some questions such as complicated carbon and nitrogen transformation pathways, unclear relationships among different biochemical processes and arguable coordination/competition mechanism among functional bacteria are remained in the ADSF system. Therefore, the nitrogen removal mechanism is required to be further investigated..In this project, municipal wastewater is selected as treatment object. Based on previous studies relevant to the PN+ADSF process established, the intrinsic mechanism of ADSF system will be investigated, and the optimal operational strategy of the PN+ADSF process will be put forward. Research innovations and features are as follows, 1) By using methods such as isotope tracer and metagenomic analysis, the coordination/competition mechanism among different biochemical processes as well as functional bacteria in the ADSF system will be identified. 2) The relationship between sludge fermentation degree and partial nitrification stabilization in the PN system will be revealed. 3) Process control parameters and operational strategy for enhancing nitrogen removal performance will be determined. In the end, research results will provide theoretical support and technical consultation for stable and energy-saving nitrogen removal from municipal wastewater.

实现稳定低耗脱氮是城市污水脱氮工艺的重要发展方向。申请人提出了部分短程硝化+同步厌氧氨氧化/反硝化耦合污泥发酵（PN+ADSF）新工艺，其中ADSF系统结合自养/异养脱氮生化过程，可在污水稳定脱氮的同时实现低耗脱氮。但该系统存在碳氮转化途径复杂、各生化反应间和不同功能菌群间协同竞争关系尚不明确等问题，因此研究ADSF系统脱氮生化过程协同竞争机制十分必要。.本项目以城市污水为处理对象，在已建立的PN+ADSF工艺初步研究基础上，探究ADSF系统内在机制，提出PN+ADSF工艺优化运行策略。研究特色和创新点包括：1)采用同位素示踪和宏基因组测序分析等手段，明确ADSF系统中生化反应间和功能菌群间的协同竞争关系；2)揭示前置PN系统中污泥发酵程度与短程硝化稳定维持的关系；3)确定增强工艺污水脱氮性能的控制参数和运行策略。研究结果可为城市污水稳定低耗脱氮提供理论支持和技术参考。

如何实现稳定低耗的氮素脱除是城市污水生物脱氮领域研究的重点和难点，对自养/异养脱氮工艺协同竞争机制进行深入研究十分必要。获资助以来，本项目采用连续长期工艺运行、批次活性测试及菌群分析等方法，以实际和模拟城市污水为研究对象，研究了部分短程硝化+同步厌氧氨氧化/反硝化耦合污泥发酵（PN+ADSF）工艺及相关拓展工艺的协同竞争机制。应用羟胺选择性抑制、游离亚硝酸（FNA）、全面抑制氨氧化菌（AOB）和亚硝酸盐氧化菌（NOB）后优先恢复AOB活性等策略揭示了短程硝化形成、维持、破坏、恢复的规律，为城市生活污水自养/异养脱氮生化过程提供有力保障；构建了有效容积10m3中试规模的PN+ADSF工艺，同时实现出水总无机氮浓度10.0mg/L及污泥减量率42.3%，证实了该工艺对于实现深度脱氮和污泥减量是可行的；分别对ADSF系统中厌氧氨氧化、短程反硝化等生化反应进行针对性探究，为揭示脱氮协同竞争机制提供了理论参考；针对内源短程反硝化、厌氧氨氧化和反硝化除磷（SNPR）、短程硝化-同步厌氧氨氧化/内源短程反硝化（PN-SAEPD）等工艺的脱氮性能、影响因素与群落特征进行了探究，为PN+ADSF工艺拓展奠定基础。以上研究内容对于降低污水处理过程无效能耗，实现城市污水稳定低耗脱氮具有重要意义。.在本项目的支持下，发表学术论文14篇，其中SCI论文13篇，申请相关发明专利2项；2人晋升副高级职称，培养博士研究生2名，硕士研究生4名。