固体缓释碳源协同短程硝化反硝化生物膜脱氮调控及运行机制研究

目前，我国城镇污水厂进水碳源浓度普遍偏低，致使出水总氮难以持续稳定达标。利用固体缓释碳源作为反硝化碳源和生物填料，构建基于亚硝酸盐途径的短程硝化反硝化生物膜脱氮工艺，是解决污水厂碳源不足和总氮高效去除的有效途径之一。但该工艺的优化调控、氮污染物形态转化和运行机制等问题仍需进一步深入研究。基于此，本项目拟采用序批式生物膜反应器，通过调控系统参数，建立固体缓释碳源协同短程硝化生物膜的最佳运行条件，明确亚硝酸盐氧化菌（NOB）抑制机制；分析生物膜形成过程中微生物胞外聚合物（EPS）关键组分和物化特性，探索其形成特性；采用化学分析与光谱表征相结合的手段，分析短程硝化系统中溶解性有机氮（DON）生成特性和生物有效性，明确其化学结构和分子构成；在此基础上，通过分子生物学技术明确短程硝化生物膜脱氮关键功能基因和优势种群演变，揭示其微生物作用机制。本项目的研究成果对推动新型生物技术发展和应用具有指导意义。

At present, the influent carbon source concentration of China’s urban sewage treatment plants is generally low, resulting in the difficulty in the continuous and stable reaching the standard of the effluent total nitrogen (TN). Solid slow-release carbon source is often used as denitrification carbon source and biological filler by combination of partial nitrification-denitrification biofilm based on nitrite pathway, which is one of the effective ways to solve the shortage of carbon source and efficient removal of total nitrogen in WWTP. However, the optimization regulation, nitrogen transformation and operation mechanism of the process still need to be further studied. Therefore, this project intends to apply a sequencing batch biofilm reactor to achieve the optimal operating conditions of slow-release carbon source synergistic partial nitrification biofilm through regulating system parameters, and the inhibition mechanism of nitrite oxidizing bacteria (NOB) will be also analyzed. Next, the key components and physicochemical characteristics of extracellular polymer substances (EPS) during the formation process of slow-release carbon source synergistic partial nitrification biofilm will be analyzed. Moreover, the characteristics of biofilm formation will be explored. Additionally, the characteristics and bioavailability of dissolved organic nitrogen (DON) in the slow-release carbon source synergistic partial nitrification biofilm will be analyzed by using chemical analysis and spectroscopic approach. In the end, the key functional genes and dominant population evolution of biofilm will be investigated by using modern molecular biology to confirm the microbial mechanism. This research result of the project is of guiding significance for promoting the development and application of new biotechnology.