Nitrogen transport and sources in urban stormwater with different rainfall characteristics

Shihui Wang; Yukun Ma; Xiaoyue Zhang; Yu Yu; Xuehui Zhou; Zhenyao Shen

doi:10.1016/j.scitotenv.2022.155902

Nitrogen transport and sources in urban stormwater with different rainfall characteristics

Sci Total Environ. 2022 Sep 1:837:155902. doi: 10.1016/j.scitotenv.2022.155902. Epub 2022 May 11.

Authors

Shihui Wang¹, Yukun Ma², Xiaoyue Zhang¹, Yu Yu¹, Xuehui Zhou¹, Zhenyao Shen¹

Affiliations

¹ State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, 19 Xinjiekou Outer Street, Beijing 100875, PR China.
² State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, 19 Xinjiekou Outer Street, Beijing 100875, PR China. Electronic address: ykma@bnu.edu.cn.

PMID: 35568184
DOI: 10.1016/j.scitotenv.2022.155902

Abstract

Nitrogen pollution in urban stormwater has led to serious quality issues in urban water. Nitrogen pollution mitigation requires fully understanding the transport process and major nitrogen sources in urban stormwater. In this study, the concentrations and flux of various nitrogen forms during urban stormwater transport were analyzed. It was found that the concentration and flux of NO₃^--N and NH₃-N decreased in the order of roof runoff, road runoff, and drainage runoff, while the concentration and flux of dissolved organic nitrogen (DON) and particulate nitrogen (PN) were found to be the highest in road runoff. Source quantification found that roof runoff (34%) and rainwater (34%) were the main contributors to nitrate pollution during light and moderate rains (<25 mm), while road runoff was identified as the major source (49%) of nitrate pollution during heavy rains (>25 mm) due to the large road runoff volume. Regarding particulate organic nitrogen (PON), the road runoff in commercial areas contributed most (23%) to PON pollution during light and moderate rains, while the runoff generated from pervious surfaces and drainage sediments were the primary two sources (22%) of PON during heavy rains. Moreover, the influence of rainfall characteristics on nitrate and PON source contributions was identified. The results show that antecedent dry periods were an important factor influencing nitrogen source contributions during light and moderate rains, while rainfall amount and intensity were critical factors impacting the nitrogen source contributions during heavy rains. Taking various transport processes, source contributions, and rainfall characteristics into consideration, several recommendations were given for the mitigation of nitrogen pollution in urban stormwater. This study can provide a useful perspective to understand the transport and sources of nitrogen, thus developing constructive strategies to control urban nonpoint source pollution management.

Keywords: Nitrate; Nitrogen; Particulate organic nitrogen; Rainfall characteristics; Source contribution; Transport process.

MeSH terms

China
Environmental Monitoring
Nitrates
Nitrogen* / analysis
Organic Chemicals
Rain
Water Movements
Water Pollutants, Chemical* / analysis

Substances

Nitrates
Organic Chemicals
Water Pollutants, Chemical
Nitrogen