珠江入海口水体中多氯联苯及其归趋分析

DISTRIBUTION AND FATE OF POLYCHLORINATED BIPHENYLS(PCBs) IN THE RIVERINE WATER OF THE PEARL RIVER DELTA

以气质联用仪检测了珠江八大入海口水样中19种PCBs单体.结果显示：PCBs在溶解相和颗粒相中的总含量分别为0.02~2.55 ng/L和0.05~5.14 ng/L;水体PCBs的logKoc′范围为4.70~5.18,与其logKow值表现为非线性相关,表明水体溶解相与颗粒相间PCBs分配的非平衡状态;第三相胶体相吸附了滤液中2.3%~52.6%的PCB单体;入海口区域的PCBs水气交换净通量约为-1.41×102ng/（m2.d）,PCBs表现为水体向大气的扩散,入海口水体可能是周边大气中PCBs的重要输入源.

Nineteen PCBs（polychlorinated biphenyls） congeners were detected in riverine water samples collected at eight outlets of the Pearl River Delta（PRD） via gas chromatography mass.Total PCBs concentrations in the dissolved and particulate phases were 0.02~2.55 ng/L and 0.05~5.14 ng/L,respectively.The log K′oc of PCB congeners in water ranged from 4.71 to 5.18,and a nonlinear correlation between the observed log K′oc and log Kow for PCBs was found,suggesting nonequilibrium state for PCBs between the dissolved and particulate phase.The ＂third phase＂colloidal phases adsorbed 2.3%~52.6% of PCB congeners in filtrate.Total net air-water exchange flux of PCBs in the outlets was-1.41×102 ng/（m2·d）,suggesting net fluxes of total PCB congeners from water into air in the PRD,and the water body as an important source of local atmospheric PCBs.