Study on copper complexing ligand concentrations in several China's coastal waters

Copper complexing ligand concentrations in the Daya Bay,Qingdao coast,Jiaozhou Bay,South China Sea and Huanghe Estuary waters were determined by the anodic stripping voltammetry technique.The distribution regularity and the relationship with other parameters were discussed.The results were as follows:Copper complexing ligand concentrations of the South China Sea were a little higher than those of other sea areas,and they were apparently higher than those of the ocean.Compared with the subsurface layer (SSL) in the sea surface microlayer copper complexing ligand concentrations showed an enrichment phenomenon,of which the mechanism is similar to dissolved organic matter.The metal complexing ligand concentration profiles of the South China Sea showed that the value in the sea surface was the highest,then it decreased with depth accruing,and a higher value appeared at the bottom.Copper complexing ligand concentrations were higher than those of cadmium and lead.Ligands in each sea area exhibited a complicated property.In short,the distribution regularity of copper complexing ligand concentrations in China's coastal waters was consistent with that of other regions in the world.Meanwhile,the positive relationship between the copper complexing ligand concentrations and biological oxygen demand,chemical oxygen demand,dissolved organic carbon,and viscosity were found clearly.