含氮污染物在城市给水系统中转化机制与控制原理

The complex of pollutants in water source seriously influences the purification efficiency of treatment processes and water quality safety in transportation, in which nitrogenous pollutant become one of hot issues. Now, there is less information on the migration and transformation, effective purification and water quality risk control of nitrogenous pollutant in urban water supply system. In this project, the feature of nitrogenous pollutant and its migration as well as transformation is investigated as follows: the effective detection method for organic nitrogen is firstly established and then the source of pollutant is classified according to the pollutants' feature. The scientific evidence for the choice of targeted pollutants used in the treatment process is provided through the investigation of nitrogenous species' migration and transformation as well as spatio-temporal variation. According the physico-chemical and biochemical treatment methods adopted in drinking water treatment process, the transformation between different nitrogenous species and its response to the main influencing factors are investigated using different treatment methods for removing nitrogenous pollutants, and then the control principle for nitrogenous pollutants is established when the whole treatment processes are considered as targeted system. The occurrence mode and the release mechanism of nitrogenous pollutant from sludge water are investigated, and then the migration and transformation of nitrogenous species and its influence on the purification efficiency of treatment processes are ensured when the sludge water is used for reuse. The reuse approach and control principle of sludge water are established to ensure the water quality safety. The migration and transformation of nitrogenous species and its influence on water quality risk are studied, and then the safe disinfection methods and the effective control means of water supply are established according to the investigation of nitrogenous pollutant.

水源污染的复杂性对水处理工艺净化效能与安全输配提出严峻挑战，其中城市给水系统中含氮污染物成为业内关注的热点问题，目前针对含氮污染物在给水系统中的迁移转化规律、高效净化原理与水质安全风险控制的研究尚不多见。本项目基于含氮污染物在城市水系统中的水质特性及其迁移转化规律，以水源水中含氮有机物高效检测方法研究为基础，明晰污染物来源，确立含氮污染物在水源水多相体系中的迁移转化规律及其时空变化规律，为水处理过程控制提供依据；基于水处理过程中物化-生化作用方法，研究不同方法和作用原理下含氮污染物转化机制与主控要素间的响应关系，建立全流程的含氮污染物控制原理；研究含氮污染物在排泥水中的赋存形式与释放行为，探讨其在排泥水回用过程中迁移转化及其对净化效能的影响机制，建立排泥水安全回用途径与控制原理；研究输配过程中含氮污染物迁移转化及其对水质风险的影响机制，建立面向含氮污染物的安全消毒与输配过程控制原理。

水源污染的复杂性对水处理工艺净化效能与安全输配提出挑战，其中城市给水系统中含氮污染物成为业内关注的热点，其核心问题是明确含氮污染物在给水系统中的迁移转化规律，建立高效净化原理与水质安全风险控制方法。本项目基于城市给水系统中含氮污染物在“水源—原水输送—工艺净化—饮用水输配”全过程中迁移转化及其影响要素，开展净化原理与水质风险控制研究。建立了介孔碳材料改性PES复合纳滤膜预处理方法，以提高有机氮（DON）与溶解性无机氮共存状态下DON的分离效果，实现DON高效检测。以太湖流域饮用水水源为对象，通过水源地含氮污染物变化及其源解析，明确冬、春季水源中含氮污染物主要以硝酸盐氮为主，夏、秋季则主要以亲水性、小分子DON为主，研究并提出饮用水处理中应重点关注DON及其含氮消毒副产物前体物的去除，以提高水质风险控制水平。基于壳聚糖复合改性研制新型复合絮凝剂，以水源水中藻源性DON为去除对象，提出了适应不同季节水质特征的差异化技术方案；以强化水中藻类蛋白、氨基酸等典型DON有效去除为目的，研发新型磁性介质材料，建立饮用水新型介质预处理方法；明确了氧化去除DON的反应路径，基于含氮消毒副产物前体物控制，提出高锰酸钾/磁性复合吸附剂联用预处理技术。明确了排泥水中DON主要为颗粒态和溶解态两种赋存形式，基于不同工艺单元排泥水的水质特点，提出沉淀池排泥水亚铁/过硫酸盐（PMS）/超滤回收技术，基于毒理学效应的砂滤池反冲洗水直接回用方法和炭池反冲洗水直接超滤净化回收技术。明确了原水输送中管壁生物膜促进了含氮污染物的硝化反应及其路径，发现了微生物代谢作用释放出更多的小分子DON，提出预氯化对其进行有效控制的方法。针对饮用水长距离输配的水质调控，提出中途补氯优化方法，以改善管道中余氯分布的均匀性和控制消毒副产物生成量。