RESUMEN
To identify emerging contaminants ï¼ECsï¼ in rainwater is a topic that has gradually received widespread attention. Rainwater resources, specifically urban roofs, play a crucial role in utilizing rainwater efficiently by understanding the occurrence and migration characteristics of pollutants in precipitation. This study selected a typical roof and studied the differences in rainwater quality and pollution occurrence at different collection stages during six rainfall events from March to May in 2023. Principal component analysis ï¼PCAï¼ and correlation analysis were used to explore the distribution, migration, and transformation of ECs in the collection process of roof rainwater. The findings revealed the presence of 44/54 ECs in wet deposition, dry and wet deposition, and roof runoff processes, with a total concentration range of 63.0 to 432.4 ng·L-1 and an average concentration of 166.8 ng·L-1. Notably, bisphenol A ï¼BPAï¼ exhibited the highest concentration, ranging from 14.7 to 265.6 ng·L-1, with an average concentration of 62.5 ng·L-1, followed by ofloxacin ï¼OFXï¼ and ethylhexyl methoxycinnamate ï¼EHMCï¼, with detected concentrations up to 45.5 ng·L-1 and 44.8 ng·L-1. Dissolved organic matter ï¼DOMï¼, nitrogen pollutants, and particulate matter were important factors affecting the occurrence characteristics of ECs, with a mantel correlation coefficient of up to 0.98 ï¼P<0.01ï¼. Based on the analysis of different rainfall events and collection stages, variations were observed in the accumulation pathways and contribution ratios of different pollutants. The wet deposition exhibited the highest content of ECs in the initial stage, whereas the dry and wet deposition and roof runoff processes displayed higher ECs content in the later stages. Additionally, the average ECs contribution rates of dry and wet deposition to roof runoff were 21.48% and 78.52%, respectively. Due to the influence of roof material and surface roughness retention performance, over 30% of ECs, including pharmaceuticals and personal care products ï¼PPCPsï¼, endocrine-disrupting compounds ï¼EDCsï¼, and pesticides, were deposited on the roof during the runoff collection. The results of this research can provide the theoretical foundation and technical support for the identification and control of ECs in urban roof runoff and for the safe storage of rainwater.