为探讨厦门湾表层海水中重金属元素迁移过程的规律,采集九龙江上游段的淡水端样品与大嶝岛附近的海水端样品,开展影响重金属迁移过程的环境因子如盐度、PH、悬浮物(SPM)、总有机碳(TOC)的模拟实验.结果表明:1)随着盐度的增加,各重金属含量均有不同程度的降低,尤其是Cu、zn和Cd,盐度增加到31.539 1时,含量仅约为淡水端含量的60%;2)随着PH的增加,各重金属含量亦有不同程度的降低,尤其是zn和Cd,PH增加到8.30时,含量仅分别为淡水端含量的20%和40%左右;3)随着SPM含量的增加,各重金属含量均有不同程度的增加,尤其是zn和Pb,SPM增加到427.3Mg/l时,含量分别为淡水端含量的45倍和8倍左右;SPM与Cr之间存在显著的线性负相关关系,随SPM含量的增加,Cr含量略有下降,但降幅不大,SPM增加到427.3Mg/l时,Cr含量仍约为淡水端含量的80%;4)随着TOC含量的增加,各重金属含量均有不同程度的增加,尤其是Cu、zn和Cr;5)在天然水体多因素的共同作用下,重金属与盐度、PH及SPM之间仍存在线性相关,但受其影响的程度要较单个因素影响小;重金属与TOC之间亦存在正相关,但较单个因素影响不同.综上所述厦门湾表层海水重金属含量在从河口向外海扩散过程中,受环境因子的影响作用是较为复杂的,其迁移过程的规律具有复杂性.The single factor and mixing simulation experiments of freshwater end in Jiulong River Estuary and seawater end in Dadeng Island in Xiamen Bay were taken to discuss the effects of environmental factors including salinity,pH,suspended matter(SPM) and total organic carbon(TOC) on heavy metals including Cu,Pb,Zn,Cd and Cr in migration process.The results of single factor simulation experiments indicated that salinity,pH,SPM and TOC were the main influencing factors of these five heavy metals during the spread process from estuary to open sea due to significantly correlated with heavy metals.1) The concentration of heavy metals decreased on a different degree with the increase of salinity.When salinity was 31.539 1,the concentration of Cu,Zn and Cd were about 60% of those in freshwater end;2) The concentration of heavy metals all went down with the increase of pH.When pH was 8.30,the concentration of Zn and Cd were only 20% and 40% of those in freshwater end,respectively;3) With the increase of SPM,the concentration of Cu,Pb,Zn and Cd increased while that of Cr decreased on a lesser degree.When SPM increased to 427.3 mg/L,the concentration of Zn and Pb were about 45-fold and 8-fold in freshwater end while the concentration of Cr were about 80% of that in freshwater end;4) The concentration of heavy metals especially Cu,Zn and Cr increased with the increase of TOC.The mixing simulation experiment showed that under the multi-factor functions in natural water,heavy metals were still correlated with salinity,pH and SPM but on a lesser degree and correlated with TOC in a different way.In a word,the effects of environmental factors on heavy metals in surface seawater were complicated during the migration process from estuary to open sea in Xiamen Bay.国家海洋局公益性项目(2011418015); 国家海洋局第三海洋研究所基本科研业务费(海三科2011014
