城市不同功能区径流中PCBs的污染特征及毒性评价

Pollution characteristics and toxicological assessment of PCBs in urban runoff

选取温州不同城市功能区小区路面、停车场、汇流口、小区屋面以及交通干道作为研究对象,采集径流样品测定了14种多氯联苯(PCBs)的浓度,并对其进行多元统计分析,探讨了其可能的污染来源.结果表明,不同城市功能区径流中PCBs含量和检出率有所差别但变化不大,其中小区屋面要高于交通干道、汇流口、停车场和小区路面(均值分别为337.9,306.3,240.1,193.2,172.7ng/L);径流中以五氯代PCBs为主,占到总量31.4%～56.2%;径流中PCBs跟SS浓度相关性较差;由多元统计分析结果可以看出,高低氯代PCBs污染来源不同;TEQs在汇流口、小区路面、停车场径流中浓度相对较大,分别达到4.4,4.1,4.0ng/L,这跟其径流中CB126含量较高有关.

Concentrations of fourteen polychlorinated biphenyls （PCBs） in runoff samples were investigated, which collected from the different sites in the city, road in residential area, parking lot, drainage outlet, roof and main transport road. The source of PCBs in urban runoff was explored using multivariate statistical analysis. The results showed that the concentrations and detection rate of PCBs varied at different site in a small range. PCBs concentration in roof runoff was higher than that in main transport road, drainage outlet, parking lot and residential area road runoff （mean values were 337.9, 306.3, 240.1, 193.2,172.7ng/L）. PCBs in runoff were dominated by penta-CBs, which occupied 31.4%-56.2% of total PCBs. There was no significant correlation between the concentrations of PCBs and SS. Multivariate statistical analyzing demonstrated that high and low chlorinated PCBs in runoff came from different sources. Moreover, values of 2,3,7,8-tetrachlorodibenzodioxin （TCDD, dioxin） equivalents （TEQs） in drainage outlet, residential area road and parking lot runoff were relatively higher （up to 4：4, 4.1, 4.0 ng/L, respectively）, which might be related with the higher concentrations of CB 126.