上海城市屋面径流PAHs赋存特征及其生态风险评价

为研究城市屋面径流中16种US EPA优控多环芳烃(PAHs)的污染特征,采集并分析了上海3次降雨事件典型屋面径流中颗粒相和溶解相PAHs的质量浓度,对屋面径流中PAHs的质量浓度特征、动态变化过程、来源解析以及潜在的生态风险进行了分析与讨论.结果表明,屋面径流中溶解相∑16PAHs的质量浓度为33.9~581.5ng/L,颗粒相PAHs的质量浓度为134.6~27528ng/L,3种屋面径流PAHs含量基本为:瓦屋面水泥屋面沥青屋面;不同类型的屋面径流中PAHs组分具有明显的相似性,均以3~4环组分为主,苯并a]芘Ba P的场次降雨事件平均浓度(EMC)值为17.4~378.5ng/L,超过我国规定的污水中Ba P排放标准.源解析结果表明,瓦屋面径流中PAHs的主要来源为机动车排放源和燃煤源;沥青屋面和水泥屋面径流中PAHs主要来源于机动车排放源、燃煤源和石油类泄露和挥发源.屋面径流中PAHs毒性当量浓度为6.08~16.86ng/L,超过我国规定的标准限值,对环境存在一定的危害,应引起足够的重视.

Concentration characteristics and related ecological risk assessment in roof runoff in Shanghai

Roof runoff samples of three rainfall events were collected at three different sites in Shanghai during the rainy season of 2014. Samples were analyzed for PAHs in both particle phase and dissolved phase, including pollution characteristics, dynamic variation, source apportionment and ecological risk of PAHs. Results indicated that the dissolved PAHs concentrations varied from 33.9 to 581.5ng/L, while the concentrations in the particle phase ranged from 134.6 to 27528ng/L.PAHs concentrations differed in three sampling sites: tile roof > concrete roof > asphalt roof. Three and four rings PAHs were the dominant components. The EMC value of BaP was 17.4~378.5ng/L, much higher than the applicable discharge standard of BaP in China. The PAHs in tile roof runoff originated mainly from vehicle emission and coal combustion, whereas the PAHs in concrete and asphalt roof runoff were mainly from vehicle emission, coal combustion and oil spill. The TEQ value of PAHs in roof runoff was 6.08~16.86ng/L, much higher than the applicable discharge standard of China, which should be brought to the attention of relevant departments.