Immobilized Biofilms on Granular Activated Carbon for Removal and Accumulation of Heavy Metals from Contaminated Streams

Abstract

Biofilms consisting of a matrix of exopolysaccharide and microorganisms developed over granular activated carbon (GAC) enhance metal uptake from solution several times more than that achieved by GAC alone. By specifically employing GAC, there is also the opportunity of developing biofilm/GAC systems that can both entrap metals and also adsorb, and ultimately degrade, polluting organic residues such as pesticides. Targets for this type of process could be dump site leachates, mine tailings and other industrial wastes. The conditions under which the biofilm is developed, including pH and temperature have, therefore, been studied in terms of subsequent influence on metal bisorption.