渤海湾及其邻近河口区重金属环境背景值和污染历史

THE ENVIRONMENT BACKGROUND VALUES OF HEAVY METAL AND POLLUTION HISTORY IN BOHAI BAY AND ITS ADJACENT ESTUARY AREAS

用长箱式静压取样器和挖探槽采集了渤海湾及毗邻河口区11个沉积物岩芯样.结合^(210)Pb测年、沉积物重金属分析,测定了沉积速率、重金属环境背景值及渤海湾4个时期(1983,1974,1964,1933年)Cu、Pb、Zn、Cd的人为增量部分.研究表明,测区沉积速率范围为1.8—44.2mm/a.高速沉积区位于蓟运河口、海河口及废黄河口;低速率区位于湾中部.Cu、Pb、Zn、Cd环境背景值分别为24.80—25.63mg/L、15.96—16.55mg/L、72.58—74.61mg/L和0.10—0.12mg/L.经重金属沉积通量计算,人为排放最大负荷量分别为:Cu,73.75t(1964年);Pb,64.57t(1974年);Zn,249.32t(1983年);Cd,5.77t(1983年).

Eleven sediment drilling cores were obtained with the long-box and static pressure sampler in Bohai Bay and its adjacent estuary areas during the year of 1983-1985. Based on 210Pb age dating and the analysis of heavy metals in sediments, the sedimentation rate, the environment background values and the artificial increment of Cu, Zn,Pb, Cd in 4 periods in Bohai Bay are determined. The range of sedimentation rate is 1.8-44.2 mm/a. The high sedimentation rate is in Jiyunhe River mouth, Haihe River mouth and the old Yellow River mouth; the low sedimentation rate is in the middle part of the bay. According to the calculation of sedimentation flux of heavy metals, the greatest discharge of Cu into the bay was in 1964 and the load was 73.751; the most discharge of Pb reached the highest in 1974 and the load was 64.57t; the discharge of Zn, Cd appeared in 1983 and the loads were 249.32, 5.77t separately.