Different influencing states of the source input on Cd in Jiaozhou Bay

Using investigation on Cd in May and August 1990, this paper analyzed the different influencing states of input source on the changes of Cr contents in Jiaozhou Bay. Results showed that in May and August 1990, Cd contents in bottom waters in Jiaozhou Bay were 0.11-0.35 μg L⁻¹ and 0.18-0.48 μg L⁻¹, respectively. The pollution level of the Cd in bottom waters in Jiaozhou Bay in 1990 was still very slight. There were four different states in the influencing process of source input on Cd: 1) when there is no source input, Cd contents are homogeneous in waters, 2) when the sediment is just beginning, Cd contents are relative high in surface waters yet relative low in bottom waters, 3) when the sediment is ongoing, Cd content are relative high in both surface and bottom waters, and 4) when the sediment is over, Cd contents are homogeneous in waters. The different influencing states of source input on Cd in Jiaozhou Bay were demonstrated by the block diagram model.