Biofilm covered granular activated carbon for decontamination of streams containing heavy metals and organic chemicals

A comprehensive biofilm of bacteria bound together in an excreted polysaccharide matrix and attached to granular activated carbon (GAC), is shown to enhance both rate and quantity of metal uptake from contaminated solutions. Electron micrographs illustrate an open film that provides a high surface area for biosorption of metal ions such as cadmium, copper, zinc and nickel. Studies have provided data on both equilibrium loadings (mg metal/g adsorbent) and adsorption rate coefficients. This data indicated the superior performance of the biofilm. This system, employing GAC as a biofilm support, has been demonstrated to both entrap metals and also adsorb other contaminants, including an organic residue (atrazine).