Department of Food, Agricultural, and Biological Engineering, The Ohio State University, 590 Woody Hayes Dr., Columbus, OH 43210, USA; Department of Civil, Environmental, and Geodetic Engineering, The Ohio State University, 2070 Neil Ave., Columbus, OH 43210, USA.
Agronomy and Soils, Agricultural Technical Institute, The Ohio State University, 1328 Dover Road, Wooster, Ohio 44691, USA.
Water Res. 2023 Jul 1;239:120036. doi: 10.1016/j.watres.2023.120036. Epub 2023 May 2.
Urban stormwater conveys dissolved pollutants, micropollutants, particulate matter, natural debris, and anthropogenic macrodebris to receiving waters. Though it is widely recognized that anthropogenic macrodebris mobilized by stormwater contributes to global pollution management issues (e.g., ocean garbage patches), these materials often are not the focus of stormwater sampling campaigns. Furthermore, macrodebris can cause clogging of sewer systems, exacerbating flooding and public health hazards. Due to their engineered structures draining directly connected impervious areas (e.g., catch basins, inlets, and pipes), roads present a unique opportunity to mitigate the conveyance of macrodebris in stormwater. To optimize control measures, data are needed to understand expected volume and mass of macrodebris in road runoff. To address this gap in knowledge, a field monitoring study was conducted in Ohio (USA) to quantify the mass, volume, and moisture content of macrodebris transported by road runoff. Designed to filter macrodebris (i.e., material with diameter greater than 5 mm) while maintaining drainage, purpose-built inserts were deployed in catch basins at eleven geographically diverse locations across the state. Macrodebris samples were collected from the inserts every 11.6 days (mean) over a two-year monitoring period. Volume and mass of total and categorical (i.e., vegetation, cigarettes, plastic, glass, metal, wood, fabric, gravel, and paper) debris were characterized. Mean total macrodebris volume and mass were 4.62 L and 0.49 kg per sampling window, corresponding to mean volumetric and mass loading rates of 8.56 L/ha/day and 0.79 kg/ha/day, respectively. Natural debris (e.g., vegetation) was the primary contributor to macrodebris (mean 80.3% (i.e., 3.94 L of the mean 4.66 L total sample volume) and 79.7% (i.e., 0.42 kg of the mean 0.53 kg total sample mass) of total volume and mass, respectively), and exhibited seasonal peaks in autumn due to leaf drop. Road functional class (i.e., interstate, principal arterial, and minor arterial routes), land use, and development density significantly impacted macrodebris generation, with increased total and categorical macrodebris along urbanized interstate highways near commercial and residential areas. Macrodebris moisture content was highly variable (ranging from 1.5 to 440%; mean 78.5%), indicating additional management (e.g., drying, solidification) may be required prior to landfilling. Results of this study inform macrodebris mitigation strategies and required maintenance frequencies for pre-treatment devices for other stormwater control measures treating road runoff, including catch basin inserts and hydrodynamic separators, among others.
城市雨水将溶解的污染物、微污染物、颗粒物、自然碎屑和人为大碎屑输送到受纳水体中。尽管人们普遍认识到，受雨水驱动的人为大碎屑对全球污染管理问题（如海洋垃圾带）有贡献，但这些物质通常不是雨水采样活动的重点。此外，大碎屑会导致下水道系统堵塞，加剧洪水和公共健康危害。由于其工程结构直接将雨水从连接的不透水区域（如雨水口、入口和管道）排出，道路为减轻雨水输送大碎屑提供了独特的机会。为了优化控制措施，需要了解道路径流水中大碎屑的预期体积和质量数据。为了填补这一知识空白，在美国俄亥俄州进行了一项实地监测研究，以量化道路径流水中大碎屑的质量、体积和含水量。该研究设计了专门的插件，用于在全州 11 个地理位置不同的地点的雨水口进行过滤（即，直径大于 5 毫米的材料），同时保持排水。在两年的监测期间，每 11.6 天（平均）从插件中收集一次大碎屑样本。对总碎屑和分类碎屑（即植被、香烟、塑料、玻璃、金属、木材、织物、砾石和纸张）的体积和质量进行了特征描述。总大碎屑的平均体积和质量分别为每个采样窗口 4.62 升和 0.49 千克，相应的平均体积和质量负荷率分别为 8.56 升/公顷/天和 0.79 千克/公顷/天。自然碎屑（如植被）是大碎屑的主要贡献者（平均占 80.3%（即平均 4.66 升总样本体积中的 3.94 升）和 79.7%（即平均 0.53 千克总样本质量中的 0.42 千克）），并由于落叶，在秋季出现峰值。道路功能类别（即州际公路、主要动脉和次要动脉路线）、土地利用和开发密度对大碎屑的产生有显著影响，在靠近商业区和居民区的城市化州际高速公路沿线，总碎屑和分类大碎屑都有所增加。大碎屑的水分含量变化很大（范围为 1.5%至 440%；平均值为 78.5%），表明在进行土地填埋之前，可能需要进行额外的管理（例如干燥、固化）。这项研究的结果为其他雨水控制措施处理道路径流水的预处理设备（如雨水口插件和水力分离器等）的大碎屑缓解策略和所需的维护频率提供了信息。
