Xiao Yang, Zhang Chi, Zhang Taotao, Luan Bin, Liu Jiaming, Zhou Qiang, Li Chentao, Cheng Haoke
College of Water Conservancy and Hydropower Engineering, Hohai University, Nanjing, China; School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou, China; Key Laboratory of Hydrologic-Cycle and Hydrodynamic-System of Ministry of Water Resources, Hohai University, Nanjing, China; Cooperative Innovation Center for Water Safety and Hydro Science, Hohai University, Nanjing, China.
College of Water Conservancy and Hydropower Engineering, Hohai University, Nanjing, China.
Sci Total Environ. 2024 Oct 20;948:174905. doi: 10.1016/j.scitotenv.2024.174905. Epub 2024 Jul 21.
Nutrient pollutants serve as indicative pollutants in urban stormwater runoff, and usually coexist and transport in particulate and dissolved phase in runoff, which is complex and crucial for effective pollution control. In this study, nitrogen and phosphorus runoff samples were collected during various natural rainfall events to explore its transport process over urban road surface during rainfall runoff. The results showed that nitrogen mainly exists in the dissolved phase (mean proportion: 62.04 %), while phosphorus mainly exists in the particulate phase (mean proportion: 65.58 %). More nitrogen and phosphorus are present and transported in dissolved phase in initial rainfall runoff over urban roads. Nutrient concentration changes during rainfall events were influenced by factors such as rainfall intensity and surface runoff, resulting in multiple peaks. Transport rate peak and concentration peak did not coincide. The proportion of dissolved total nitrogen in the runoff process ranged mainly between 40 % and 80 %, and the proportion of dissolved ammonia was distributed between 60 % and 100 %. The proportion of dissolved phosphorus was more evenly distributed across each proportion interval. Influenced by the differences in phase proportions, first flush processes of nitrogen and phosphorus are not the same. Urban stormwater management measures should prioritize both the initial concentration peaks and the peaks in nutrient transport rates during rainfall. This approach is essential for enhancing the efficiency of stormwater pollutant collection and treatment.
