Dongfang Yang

Cd in Jiaozhou Bay is sourced from river flow, marine current and atmosphere deposition

Many marine bays have been polluted by many pollutants, and identifying the major pollution sources is essential to pollution control. This paper analyzed the distribution and pollution source of Cd in Jiaozhou Bay in 1988. Results showed that Cd contents in surface waters in Jiaozhou Bay in April, July and October 1988 were 0.09-0.12 μg L, 0.10-1.07 μg L and 0.03-0.040 μg L, respectively. This bay had been slight contaminated by Cd in 1988. The major sources of Cd were river flow, marine current, and atmospheric deposition, whose source strengths were 1.07 μg L, 0.12 μg L and 0.04 μg L, respectively. River flow was the major Cd source in 1988 since a big part of Cd generated by human activities were washed to and delivered by river flow, and discharged to marine bay finally. Finally, a block diagram model was provided to described these three input paths via land, ocean and atmosphere.

Variations of pollution sources of Cu in Jiaozhou Bay 1982–1986

Cu pollution in marine bays has been one of the critical environmental issues in the whole world, and understanding the variations of the pollution sources is essential to environmental protection. This paper identified the sources of Cu in Jiaozhou Bay during 1982–1986, and revealed the variations of the sources. Results showed that there were five Cu sources during study years including marine current, stream flow, island top, overland runoff and marine traffic, respectively, whose source strengths were varying from 0.39–20.60 μg L-1, 0.37–10.57 μg L-1, 0.77–4.86 μg L-1, 2.28–3.56 μg L-1, 9.48 μg L-1, respectively. These findings were helpful information in decision-making of pollution control and environmental remediation practice.

Different stages of Cd’s transporting process in waters in Jiaozhou Bay

Cd pollution in marine bays is one of the critical environmental issues, and understanding the stages of transporting process of Cd in marine bays is essential to pollution control. This paper analyzed the stages of Cds transporting process in waters in Jiaozhou Bay during 1979–1983. Results showed that the transporting process in waters in Jiaozhou Bay included seven different stages of 1) the sedimentation of Cd content was beginning, 2) the sedimentation of Cd content was increasing, 3) the sedimentation of Cd content was increasing greatly, 4) the sedimentation of Cd content was beginning to decrease, 5) the sedimentation of Cd content was decreasing stably, 6) the sedimentation of Cd content was beginning to stop, and 7) the sedimentation of Cd content was beginning to fully stop. In according to the different stages of Cds transporting process in waters, the changing trends of Cd contents in surface and bottom waters and their relationships could be defined and predicted.

Vertical transferring process, mechanism and model of Pb in Jiaozhou bay

This paper analyzed the vertical transferring process, mechanism and model of Pb in Jiaozhou Bay based on investigation of Pb in surface and waters in different seasons during 1979-1983. Results showed that the Pb contents in surface waters were changing with seasons within year, and Pb contents in bottom waters were influenced by which in surface waters by means of vertical transferring. The mechanism of the vertical transferring process was revealed. The vertical transferring process was containing three stages as, 1)Pb was transferring to surface waters in the bay, 2)Pb was transferring to bottom waters, and 3) Pb was fixing to the sediment and leaving the waters. Furthermore, a block diagram model was established to describe the transferring process and variations of Pb in waters.

The environmental dynamic value and model of Cr in marine bay

We applied the definition and structural model of environmental dynamic value of substance in marine bay and the variables including basic background value, environmental background value, input value and environmental dynamic value in analyzing the change process and change trend of Cd in Jiaozhou Bay, eastern China based on investigation data on Cd in May, August and November 1979. Results showed that the basic background value of Cd was 0.02-0.04 μg L, the environmental background value of Cd was 0.01-0.04 μg L, the input of Cd from river flow was 0.07-0.85 μg L, the input of Cd from marine current was 0.25 μg L, and the environmental dynamic value of Cd was 0.01-0.85 μg L. The identification of change process and the change trend of Cd provided scientific basis for division of grade standards of Cd in marine bay.

The back and forth transformation between homogeneity and heterogeneity of Cd in marine bay

Cd pollution in marine bay is one of the critical environmental issues, and therefore understanding the distribution characteristics of Cd is essential to environmental conservation. It has been found in previous studies that the distribution of pollutants in marine bay has feature of homogeneity, and this paper tried to analyze the mechanism of Cd’s homogeneity based on investigation data in Jiaozhou Bay, eastern China. Results showed that the distributions of Cd contents in marine bay could be transformed between homogeneity and heterogeneity. In case of little or small Cd input to the bay, the distribution of Cr was homogeneity. While in case of large input, the distribution was heterogeneity. In generally, the heterogeneity was determined by Cd input, while the homogeneity was determined by tide and marine current.

Different types of seasonal changing processes of Pb in Jiaozhou bay

This paper analyzed the seasonal variations of Pb in surface and bottom waters in Jiaozhou Bay based on investigation of Pb in surface and waters in different seasons during 1979-1983. Results showed that at temporal scale, Pb contents in bottom waters were more or less increasing/decreasing along with the increasing/decreasing of Pb contents in surface waters. Meanwhile, the sedimentation, accumulation and fixing of Pb were also important factors influencing the seasonal changing of Pb in waters. The seasonal changing of Pb contents within year in surface and bottom waters was forming different curves, i.e., Peak type, Lagged type and Superposed type. These findings would be helpful to understand the influences of the variations of Pb contents in surface to which in bottom waters, as well as the seasonal variations of Pb contents in both surface and bottom waters.