城市雨水径流重金属生物滞留净化机理及迁移特征研究

随着城市化的快速发展，由雨水径流引起的非点源污染逐渐成为环境水体污染物的重要来源。本项目针对城市雨水径流引起的重金属污染问题和生物滞留净化技术的高效、生态、易实施等特点，采用实验室量化模拟实验、现场连续监测与数值模拟研究方法，重点研究城市雨水径流重金属（Cu、Pb、Zn、Cd）生物滞留净化效果、滞留介质内部累积、赋存特性及影响因素；生物滞留介质表层累积重金属雨天淋溶释放特征及相间迁移转化规律，明确生物滞留介质内部重金属的"累积-迁移"规律与关键影响参数、重金属形态转化诱发机制与作用机理。系统分析生物滞留介质重金属净化容量与存在的潜在环境风险，建立生物滞留技术重金属"累积-迁移"预测模型，为提高生物滞留技术的净化效果、降低生物滞留技术在雨水资源化应用中存在的生态风险、实现环境中重金属总量控制提供科学依据。

With the rapid development of urbanization, no-point pollution caused by stormwater run-off became an important pollutants source of the watershed. Many studies of urban stormwater runoff have shown high levels of many pollutants, compared with other pollutants, heavy metals are of great importance in runoff due to their persistence and potential toxicity, with automobiles and buildings being major source contributors. This project aimed at the urban run-off heavy metal (Cu,Pb,Zn,Cd) pollution problem and bioretention purification technology with the characteristics of high efficiency, ecological and apt to implementation, quantitative simulated experiment, the continuous monitoring of pilot scale demonstration and numerical simulation study method were adopt, focus on to research the heavy metal removal efficiency of bioretention, accumulation and exist form changing characteristics in bioretention media, and its main effect factors. To investigate the heavy metal, accumulated on the surface layer, soluble and release characteristics in wet weather, and the partitioning characteristics between the dissolved and particulate-bound fractions of heavy metals under different conditions, "Accumulation-migration" law of heavy metal in bioretention media was analyzed, draw the conclusion of its main effect factors and form changing theory,analysis the capacity of the bioretention media removal heavy metal and potential environment risks for the heavy metal detained, then a "accumulation- migration" forecast model of heavy metal detained in the bioretention system was proposed, so as to improve the bioretention heavy metal removal efficiency, decrease the potential environment risks for the heavy metal accumulation in the bioretention media, and to provide data for heavy metal total quantity control in the environment.