Impacts of Urbanization on Stormwater Pollutant Loadings and River Water Quality

雨水/融雪径流将道路和其他城市表面积累的人为和自然污染物冲入雨水下水道，然后进入接收水体，对水质和生态系统构成重大威胁。对于加拿大和美国北方的城市来说尤其如此，冬季使用的大量道路除冰盐/沙可能在春季径流期间对接收水体产生冲击效应，据报告氯化物浓度高达加拿大急性暴露指南的600%。在快速城市化和气候变化的背景下，这种威胁将进一步加剧和复杂化。该计划的长期目标是揭示和量化城市化和气候变化对接收水体的耦合影响，并研究创新方法，以提高城市和河流/湖泊的可持续性和弹性，以最大限度地减少此类影响。在接下来的5年里，我将以埃德蒙顿和北萨斯喀彻温河为例，重点研究城市化对雨水污染物负荷和接收河流水质的影响。该计划中提出了两项研究。目标1将研究较少报道的时空变化的雨水负荷的常见但重要的污染物（营养物质，沉积物，盐），城市化水平与负荷的未报道的关系，以及被忽视的潜在冲击效应的负荷接收河流在春季径流。目标2将首次量化城市雨水中新出现的污染物（微塑料，MP）的负荷，并调查未探索的水动力学对MP在河流中的运输和归宿的影响。建议对目标1选定的雨水排放口进行现场监测，并对目标2中的中压负荷进行监测。针对目标2，将在不同水动力条件和不同MP特性（材料/密度、尺寸和形状）下，在水槽中进行MP运输和再悬浮的实验室实验。基于粒子图像测速技术、粒子跟踪测速技术和平面激光诱导荧光技术，发展了一种新颖的MP速度和浓度测量技术。目标1将对污染物负荷和河流水质进行数值模拟，目标2将对MP传输和再悬浮进行数值模拟。提案中列出的所有主要设备/软件均可在UofA的水资源组中使用。拟议的研究将产生创新的，原始的知识，城市雨水污染物负荷和运输和命运的议员在水中。研究结果还将有助于加拿大三级政府制定/调整有关城市发展和河流/湖泊最大总污染物负荷以及除冰盐/沙和雨水管理的众多计划/政策。该研究将在咨询公司、公用事业公司和政府部门非常希望的领域培训7名HQP。

Stormwater/snowmelt runoff flushes anthropogenic and natural pollutants accumulated on roads and other urban surfaces into storm sewers and then into receiving water bodies, posing significant threats to the water quality and ecosystem. This is particularly true for municipalities in Canada and the northern US where the large amounts of road de-icing salts/sands used in winter can potentially have a shock effect during spring runoff to the receiving water bodies, with chloride concentration reported as high as 600% over the Canadian acute exposure guideline. In the context of fast urbanization and climate change, such threats will be further intensified and complicated. The long-term goals of this program are to reveal and quantify the coupled impacts of urbanization and climate change to receiving water bodies and to research innovative ways to enhance the sustainability and resiliency of both cities and rivers/lakes to minimize such impacts. In the next 5 years, I will focus on urbanization impact to stormwater pollutant loadings and receiving river water quality using Edmonton and the North Saskatchewan River as an example. Two studies are proposed in the program. Aim 1 will research the less-reported temporospatial variability of stormwater loadings of common yet important pollutants (nutrients, sediments, salts), the un-reported relation of urbanization level with the loadings, and the overlooked potential shock effect of the loadings to receiving rivers during spring runoff. Aim 2 will quantify, for the first time, the loading of an emerging pollutant (microplastics, MPs) in urban stormwater, and investigate the unexplored hydrodynamic impact to MP transport and fate in rivers. Field monitoring is proposed at selected storm outfalls for Aim 1 and MP loading in Aim 2. Lab experiments will be conducted for Aim 2 on MP transport and re-suspension in a flume under different hydrodynamic conditions and with different MP properties (materials/densities, sizes and shapes). An innovative measurement technique for MP velocity and concentration will be developed based on particle image velocimetry, particle tracking velocimetry and planar laser-induced fluorescence. Numerical modeling will be conducted for pollutant loadings and river water quality in Aim 1, and MP transport and re-suspension in Aim 2. All the major devices/software listed in the proposal are available for use in the Water Resources Group at the UofA. The proposed research will generate innovative, original knowledge on urban stormwater pollutant loadings and transport and fate of MPs in water. The research results will be also useful in Canada's three levels of governments in making/adjusting numerous plans/policies on urban development and maximum total pollutant loadings to rivers/lakes, as well as on de-icing salts/sands and stormwater management. The research will train 7 HQP in areas that are highly desirable by consulting firms, utility companies and government sectors.