基于水体生态安全的再生水消毒副产物及生物源腐植酸类物质的调控研究

The accumulation of the disinfection by-products (DBPs) in water environment can increase the ecological safety and health risk during municipal wastewater reclamation and reuse process. Preliminary study showed that the microbially derived fulvic acids substances, which generated from the municipal wastewater treatment process, could increase the disinfection by-products formation potential (DBPFP) of the secondary effluent. This subject focuses on revealing the generated characteristics of microbially derived fulvic acids in the biological wastewater treatment process and investigating the control mechanism of DBPs in the wastewater reclamation process. Using chemical analysis, instrument analysis and molecular biology techniques, grasp the generation rules of microbially derived fulvic acids in typical wastewater treatment process, and identify the composition and structural characteristics of microbially derived fulvic acids. Then research the formation potential of THMs and HAAs as two typical substances of DBPs, and revise the THMs and HAAs reaction kinetic models matching chlorine disinfection unit of the wastewater reclamation process. In order to reclaimed water quality safety, based on the precursors control and DBPs control, disinfection by-products control principle in wastewater reclamation process will be researched. The theoretical and technical support to reduce environmental and healthy risk of reclaimed water and to ensure the safety of the water environmental ecological system will be obtained from this research in municipal wastewater reclamation.

城市污水再生利用过程中消毒副产物在环境中富集引发的生态安全和健康风险问题受到广泛关注。前期研究发现城市污水生物处理过程中产生的生物源腐植酸类物质会导致二级出水DBPs生成潜能明显增大。申请课题拟对城市污水生物源腐植酸类物质生成特性及再生过程中消毒副产物控制机理进行系统性研究：运用化学分析、仪器分析、分子生物学分析等手段，研究典型污水处理过程中生物源腐植酸类物质的生成规律，鉴别生物源腐植酸的组分及其结构特征；在此基础上,判明THMs和HAAs两类代表性DBPs的生成潜能，对现有的与氯消毒过程相关的THMs和HAAs的生成动力学模型进行修订；以再生水质安全保障为目的，从前体物控制和DBPs控制两个角度，研究污水再生处理过程的消毒副产物控制原理，为削减再生水利用的环境和健康风险及保障水环境生态安全提供理论和技术支撑。

城市污水再生利用过程中消毒副产物在环境中富集引发的生态安全和健康风险问题受到广泛关注。以西安市部分污水处理厂各阶段出水为对象，研究城市污水再生氯消毒过程中THMs与HAAs 的生成及其前体物的迁移转化规律，探讨其生成动力学机理及最佳消毒工艺条件。研究结果表明，污水处理厂二级出水及剩余污泥中腐殖酸均为生物源腐殖酸，其化学组成和结构表现为脂肪性成分较多、芳香性相对较弱，导致其加氯后消毒副产物生成势有所不同。通过对溶解性有机碳(DOC)、温度(T)、pH、加氯量(Cl2)和溴离子(Br-)等影响因素的相关性分析，分别建立适用于污水再生消毒过程的THMs和HAAs的线性与非线性回归模型，预估再生水中THMs和HAAs的生成量及变化规律，其中加氯量是影响THMs形成的关键的因素，加氯量和温度是影响HAAs生成的关键因素，并获得最佳的再生消毒加氯条件，实现污水再生消毒工艺的优化控制，最佳加氯点为沉淀出水处+过滤出水处、最佳前加氯和后加氯量的比例为1：1，该研究结果为再生水消毒副产物的生成以及控制提供理论依据。