Stages and Status of Vertical Transporting Process of Cd in Jiaozhou Bay

Abstract

Understanding the stages of transporting process of Cd in marine is essential to pollution control. This paper analyzed the stages and status of Cd's vertical transporting process in waters in Jiaozhou Bay during 1979-1983 showed that the vertical transporting process in waters in Jiaozhou Bay included three stages of 1) Cd was imported to the bay, 2) Cd was transported to surface waters, and 3) Cd was transported from surface waters to bottom waters. The vertical transporting process included six status of 1) the sources discharged a lot of Cd to the bay, and Cd contents in surface waters were higher than in bottom waters, 2) the input of Cd was increasing, and Cd contents in surface waters were still higher than in bottom waters, 3) the input of Cd continued, a big part of Cd was transported to bottom waters, and Cd contents in surface and bottom waters were closed, 4) the input of Cd was decreasing, and the sedimentation of Cd continued, and Cd contents in surface waters were lower than in bottom waters, 5) the input of Cd stopped, and the sedimentation of Cd continued, Cd contents in surface waters were little and were lower than in bottom waters, 6) the input of the input of Cd stopped, and the sedimentation of Cd stopped since Cd contents in surface waters were little, and Cd contents in surface and bottom waters were closed. These stages and status reveal the vertical transporting process of Cd clearly.