典型金属污染物在供水管道沉积物/水两相间迁移转化机制研究

本课题针对供水管道长期运行中金属污染物的富集、释放造成的二次污染问题，以多水源格局下供水管网水质达标为目标，综合考虑供水管网不同运行工况、不同水源水质变化及投加不同消毒剂情况下，基于管壁沉积物/水界面反应器和模拟循环管路系统对典型金属污染物（铬、钒、镉、铅等）在供水管道沉积物/水两相间的迁移转化过程进行研究；系统阐述金属污染物和管壁沉积物的吸附-解吸和共沉淀机理，以及微生物-管壁沉积物-金属污染物的生物-化学转化耦合作用机制，并建立典型金属污染物聚类树；建立基于热力学、反应动力学及水动力学的金属污染物迁移转化动力学模型。在此基础上，通过建模分析、追踪计算金属污染物在管网中的变化并进行预测预警；同时，探索供水管道中典型金属污染物释放量最小的最优工况和最佳水质因素，提出保持管网水质稳定的综合措施。本研究对控制管网金属污染物二次污染和保证供水水质达标有重要意义。

This research focuses on the secondary pollution problem of water distribution system (WDS) in the long run, which is caused by enrichment and release of metal pollutants. To guarantee the water quality of the multi-source WDS meeting the water standard，different operating conditions, water qualities and varieties of disinfectants should be considered in this study. Based on the pipe wall sediment/water interface reactor and the simulated circulation system, the progress of migration and transformation between the sedimentary and water phases of typical metal pollutants (chromium, vanadium, cadmium, lead, etc) in the WDS are studied; The adsorption-desorption and coprecipitation mechanism, together with the biological-chemical coupling mechanism between the microorganisms/pipe wall sediment/metal pollutants are illustrated systematically, further, a typical metal pollutants clustering tree are generated; In addition, the metal pollutants' migration and transformation kinetic models based on thermodynamics, reaction kinetics and hydrodynamics are developed. Based on this, the water quality pollution can be forecasted and warned through the modeling, simulation and tracking of metal pollutants in the WDS. And the optimal operation condition and water quality conditions are sought to guarantee the minimum release of metal contaminant, together, the comprehensive measures to maintain water quality stability are put forward. Finally this study is of great significance to control the secondary pollution of metals and ensure the water quality standard of the WDS.