Colloidal complexes, bioaccumulation

BIOACCUMULATION OF METALS AS COLLOID COMPLEXES AND FREE IONS A KINETIC MODEL... 

In a study of the bioaccumulation of metals as colloid complexes and free ions by the marine brown shrimp, Penaeus aztecus [29] the colloids were isolated and concentrated from water obtained from Dickinson Bayou, an inlet of Galveston Bay, Texas, using various filtration and ultrafiltration systems equipped with a spiral-wound 1 kDa cutoff cartridge. The total colloidal organic carbon in the concentrate was found to be 78 lmgdm 3. The shrimps were exposed to metals (Mn, Fe, Co, Zn, Cd, Ag, Sn, Ba and Hg) as radiolabelled colloid complexes, and free-ionic radiotracers using ultrafiltered seawater without radiotracers as controls. The experiments were designed so that the animals were exposed to environmentally realistic metal and colloid concentrations. 

Carvalho, R. A., Benfield, M. C. and Santschi, P. H. (1999). Comparative bioaccumulation studies of colloidally complexed and free-ionic heavy metals in juvenile brown shrimp Penaeus aztecus (Crustacea Decapoda Penaeidae), Limnol. Ocea-nogr., 44, 403 -14. 

The reduction and formation of colloidal gold was observed in a study on the bioaccumulation of the gold by the filamentous cyanobacterium (P. horyanum) from a Au(III) chloride complex [104]. When the bacterial samples were studied using XAS, SAED and TEM, the XAS or XANES analyses showed the presence of a mixture of different types of gold compounds, including Au(I) sulfide, gold... 

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