基于碳氮归趋模型的厌氧氨氧化-反硝化协同渗滤液深度脱氮调控及其分子机制解析

Anaerobic ammonium oxidation (anammox)-denitrification synergistic processes have been efficiently applied in the treatment of ammonium-rich landfill leachate, however, the activity of anammox bacteria may be inhibited by organic matters in landfill leachate, thus the control of organics stress is very critical. However, there is limited understanding of biological characteristics of anammox and denitrifying bacteria at the transcriptional and translational levels when treating landfill leachate, which is unfavorable for the clarification of degradation mechanisms and conversion characteristics of organic matters and nitrogen in anammox-denitrification synergistic systems; thus, it is difficult to put forward effective control measures under this condition. The current study investigate the changes in the transcriptional and translational levels of the functional genes involved in carbon and nitrogen metabolisms in anammox and denitrifying bacteria, paying attention to reveal the degradation mechanism of organic matters and nitrate in anammox bacteria, improve the transformation analysis of nitrogen and carbon, establish models related to the nitrogen and carbon mass balance in anammox-denitrification synergistic systems, and identify the molecular mechanism of partial denitrification bacteria to relieve the inhibition of high concentration of organics on anammox bacteria. The outcome of this research could clarify the metabolic properties of anammox and denitrifying bacteria in synergistic systems for advanced nitrogen removal from landfill leachate, improving the establishment of inhibition mechanism diagnosis and the proposition of specific regulation measures at molecular levels under stress conditions, and finally facilitate the stable and efficient operations of anammox-denitrification synergistic systems for advanced nitrogen removal from landfill leachate.

厌氧氨氧化-反硝化协同工艺可有效处理高氨氮的垃圾渗滤液，但渗滤液中的有机物可能对厌氧氨氧化菌造成抑制，因此有机物胁迫调控非常关键。由于未从转录和翻译等分子水平揭示厌氧氨氧化菌和反硝化菌在垃圾渗滤液处理系统中的代谢机理，导致难以阐明厌氧氨氧化-反硝化协同系统中有机物和氮的降解机制及归趋特性，因此难以提出有效调控措施。本课题拟通过考察厌氧氨氧化菌与反硝化菌胞内碳氮代谢功能基因转录与翻译水平的变化，解析厌氧氨氧化菌降解有机物和硝酸盐的代谢机制，优化厌氧氨氧化-反硝化协同系统中碳氮转化分析，并构建碳氮归趋模型，同时揭示短程反硝化菌缓解有机物对厌氧氨氧化菌胁迫的分子机理。基于转录和翻译水平阐明厌氧氨氧化菌和反硝化菌在垃圾渗滤液深度脱氮系统中的代谢特性，有助于建立基于分子水平的胁迫环境抑制机理诊断措施，并提出有针对性的调控策略，实现渗滤液厌氧氨氧化-反硝化协同深度脱氮工艺的稳定高效运行。

当厌氧氨氧化工艺用于处理高氨氮废水时，由于厌氧氨氧化菌的固碳过程必然产生11.2%（相对于进水总氮）的硝酸盐，导致出水总氮无法满足相关排放标准，这在一定程度上限制了厌氧氨氧化工艺在高氨氮废水生物脱氮领域的应用。近年来部分研究表明，在厌氧氨氧化-反硝化耦合工艺中，厌氧氨氧化菌产生的硝酸盐可被反硝化菌所利用，从而提高系统的TN去除率。然而，高氨氮废水中有机物浓度一般较高，其易刺激反硝化菌过量增殖，继而会与厌氧氨氧化菌竞争亚硝酸盐。因此，需采取有效措施防止或抑制厌氧氨氧化-反硝化耦合系统中反硝化菌的过量增殖。. 针对以上问题，本项目主要研究了联氨对厌氧氨氧化菌及反硝化菌的作用效果、厌氧氨氧化-反硝化耦合系统内反硝化菌过量增殖后联氨对耦合系统的恢复作用，以及SBR系统中，实施厌氧氨氧化与反硝化的错时反应对耦合系统稳定运行的作用。通过以上研究内容，最终建立反硝化菌过量增时厌氧氨氧化-反硝化耦合系统的抑制机理诊断措施及调控策略，为厌氧氨氧化-反硝化耦合工艺的设计、操作和优化调控提供理论依据和技术支持。