基于好氧条件下低 C/N（碳/氮）比污水氨氮脱除新技术的研究

The complete removal of ammonia-nitrogen of low carbon-to-nitrogen ratio wastewater has been concerns and difficulties of wastewater treatment research. The technology of conventional biological nitrogen removal for low carbon-to-nitrogen ratio wastewater has greater limitations. Therefore, it is of significance to study and develop a novel technology for fast and efficient ammonia-nitrogen removal of low carbon-to-nitrogen ratio wastewater. The main purpose of the study is to achieve rapid and complete ammonia-nitrogen removal of low carbon-to-nitrogen ratio wastewater in situ simultaneous nitrification and denitrification through a self-developed integrated composite porous bio-carrier of the iron-carbon (Fe-C). In the integrated composite porous bio-carrier of the Fe-C, the biofilm nitrification and autotrophic denitrification reaction within biofilm is carried out simultaneously. The research is mainly focused on to optimize and characterize the architecture of the integrated composite porous bio-carrier of the Fe-C, to establish the coupling mechanism of the biofilm and Fe-C internal electrolysis, and to clarify the dynamics of the enrichment, mass transfer, migration and oxidation-reduction reaction of pollutants, etc. in the biofilm. Eventually, a novel theoretical system and technology will be established for efficient ammonia-nitrogen removal in low carbon-to-nitrogen ratio wastewater. The novel technology has important theoretical value and broad application prospects for realizing ammonia-nitrogen emission reduction target of China's '12th Five-Year' and solving the increasingly serious water pollution and water shortages.

低C/N比污水中氨氮的彻底脱除一直是污水处理研究领域的热点和难点。 常规生物脱氮处理低C/N比污水有较大的局限性，因此研究开发低C/N比污水中氨氮快速高效脱除的新技术具有非常重要的意义。本研究拟通过研制一种能够将生物膜的好氧硝化反应和生物膜内自养反硝化脱氮反应于一体的铁炭（Fe-C）一体复合多孔生物载体，实现低C/N比污水中氨氮原位同步硝化反硝化快速彻底脱除。其研究关键点在于：1）优化和表征Fe-C一体复合多孔生物载体的架构特征；2）确立载体生物膜与Fe-C内电解反应的耦合机理；3）阐明生物膜上污染物富集、传质、迁移、氧化还原反应等界面过程的动力学原理；4）建立完整的低C/N比下污水中氨氮高效脱除的理论体系和技术方法。该项技术的研究成功，对实现我国 "十二五"污水氨氮减排目标，解决国内日益严重的水污染和水资源短缺问题有着重要的理论价值和广阔的应用前景。

低碳氮比（C/N）污水中氨氮的彻底脱除一直是污水处理研究领域的热点和难点。常规生物脱氮工艺处理低C/N比污水具有较大的局限性，故研发低C/N比污水中氨氮高效脱除新技术具有重要意义。.本项目通过研制一种铁炭（Fe-C）复合催化生物材料作为载体，将载体的内电解作用与生物膜的好氧硝化和膜内自养反硝化耦合，形成低C/N比污水氨氮高效脱除的耦合新技术。.项目首先研究了铁炭（Fe-C）复合催化生物载体的制备方法和工艺，表征和优化了Fe-C生物载体的架构特征及电化学活性；然后利用该载体培养微生物，将催化内电解与生物膜耦合，通过探究各因素对耦合体系脱氮的影响，获得了高效脱氮的最佳工艺运行参数，并通过建立的数学模型验证了耦合体系的脱氮效能；最后利用分子生物学方法探明了体系内生物多样性及种群结构，利用X射线衍射考察了铁元素在载体表面、生物膜内部及水中的化合物形态变化，并与生物分析结合，探讨了耦合脱氮机理。结果表明：1）本研究建立的耦合技术可在HRT为3.5 h时实现总氮为60 mg/L、C/N为2的污水脱氮90%以上；2）以Fe2+和H2 (或[H])为电子供体的自养反硝化菌—球衣菌属(13.1%)和噬氢菌属(9.7%)为该系统的优势菌属，表明耦合体系内反硝化以自养为主，且载体为自养反硝化原位提供电子供体，保证了氮的高效脱除；3）三价铁化合物大量存在于生物膜内，而在生物载体表面含量极低，表明生物膜对载体表面具有更新作用，避免了长期运行过程中载体的钝化；4）本项目通过载体的研制及理化性质试验、工艺连续运行、分子生物学分析及化学成分分析建立了低C/N 比污水中氨氮高效脱除的新技术及耦合脱氮机制。.本项目研究成果已成功应用于低C/N比污水脱氮工程。且基于本研究成果，已将所开发的载体延伸至厌氧自养反硝化脱氮及难降解有机废水的电化学处理研究。本项目研究成果补充了我国现有污水深度脱氮工艺的不足，为实现“十三五”污水排放总氮控制目标，解决我国日益严重的水体污染和水资源短缺问题提供了理论依据和技术支持，具广阔的应用前景。