珠江入海口水体中多氯联苯的分布特征及其来源分析

为评估珠江三角洲水体中PCBs(多氯联苯)的污染水平及其生态环境影响，于2005年3月—2006年2月，采集并分析了珠江八大入海口水体中PCBs的残留状况. 结果显示，珠江八大入海口水体中ρ(PCBs)为0.19～7.04 ng/L，其中三氯联苯和四氯联苯占PCBs总量的70%以上，约40%的水样(主要为7—12月样品)ρ(PCBs)高于或接近我国《地表水环境质量标准》(GB 3838—2002)的限值(2 ng/L). 组成分析及主成分分析结果表明，珠江入海口水体中PCBs的分布特征与我国#1PCBs及国外Aroclor 1242和Aroclor 1016产品相近，低氯产品#1PCBs及Aroclor 1242和Aroclor 1016可能是水体中PCBs污染的主要来源，而废弃电容器、沉积物再悬浮、大气沉降及废水处理厂排放等输入源是水体的重要贡献者. 

Distribution and Sources of Polychlorinated Biphenyls (PCBs) in Riverine Water of the Outlets of the Pearl River Delta

In order to estimate pollution levels of PCBs and their eco-environmental impacts in the waters of the Pearl River Delta(PRD),a large-scale sampling program was conducted to collect monthly water samples at eight major riverine runoff outlets of the PRD from March 2005 to February 2006,and to measure the concentrations of PCBs.The results showed that the PCB concentrations were 0.19-7.04 ng L,and that tri-PCBs and tetra-PCBs constituted more than 70% of the total PCB concentration in the samples.Furthermore,about 40% of the samples,mainly those collected between July 2005 and December 2005 at the outlets of the Pearl River Delta,had a total PCB concentration higher than or close to that set in the "Environmental Quality Standards for Surface Water" of China(2 ng L).Composition analysis and principal component analysis results indicated that the profile of PCBs in the samples collected was similar to that of #1 PCBs produced in China,and those of Aroclor 1242 and Aroclor 1016 produced abroad.This suggests that #1 PCB,Aroclor 1242,and Aroclor 1016 may be the main sources of PCB pollution in the riverine waters of the Pearl River Delta.In addition,PCBs from used imported capacitors,sediment resuspension,atmospheric deposition,and discharge of urban wastewater treatment plants were also important sources of PCBs in the riverine waters.