Sediments cadmium contents

Chromium, Cu, Mn, Pb and Zn presented a similar distribution trend along the studied area, even though their concentrations are completely different (Figures 6.4-6.S ). This fact suggests that these metals have a similar behaviour in the evaluated environment, probably because they are controlled by similar processes and conditions. Cadmium contents in the analysed samples are in all cases below the LoDs of the method employed (<0.09 pg g dry weight). Iron showed a particular distribution pattern (Figure 6.8), which is probably related to its abundance (38). No evidence of trace metals in surface sediments of the Potter Cove was observed that could be attributed to contamination caused by scientific or logistic activities carried out in the Jubany Station. 

In the upper part of the sediment column, total particulate cadmium content is approximately 10 mg/kg, whereas in the deeper anoxic zone 20 mg Cd/kg have been measured. The results of the sequential extractions of the core sediment samples separated at 2-cm levels (Figure 5-8) indicate, that in the anoxic zone cadmium is associated by 60-80% to the sulfidic/organic fraction. In the oxic and transition zone, sulfidic and organic fractions decrease to approximately 30-40%, whereas carbo-natic and exchangeable fractions simultaneously increase up to 40% of total cadmium concentrations. Thus, it is notable that high proportions of mobile cadmium forms correlate with the marked reduction in total cadmium contents. 

Total Cadmium Content of the Sediment Materials from Selected Sites in Louisiana and Alabama... 

Figure 5-8 Geochemical Characteristics of Core Sediments from the Heu-kenlock Intertidal Flat, and Total Contents and Chemical Forms of Particulate Cadmium (after Kersten Kerner, 1985)...

CCQM-K13 Amount content ot cadmium (Cd) and lead (Pb) in sediment... 

Zasavica/Sava confluence, and downstream sites of the river Zasavica in order Modran , Valjevac , Sumareva , Ravnjanska , Rajevica , Gajica . A sequential extraction procedure was applied for partitioning of metals into five fractions. The examined river sediment samples are very interesting because of their great surface area and content of highly adsorbing minerals that are adsorbing toxic heavy metals, for example lead and cadmium. 

Rhamnolipids were applied to a soil in the presence of oil contamination [15] and from sediments to remove heavy metals [63]. Although 80-100% of cadmium and lead can be removed from artificially contaminated soil, in field samples the results were more in the range of 20-80% [64], Clay and iron oxide contents affected the efficiency of the biosurfactants but this has not been researched. Biosurfactant could be added as a soil washing process for excavated soil. Due to the foaming property of the biosurfactant, metal-biosurfactant complexes can be removed by addition of air to cause foaming and then the biosurfactant can be recycled through precipitation by reducing the pH to 2. 

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