The removal of cadmium from water by the use of biological sorbents

Heavy metals such as cadmium, chromium, lead and zinc are liberated by a variety of industrial processes and frequently contaminate industrial effluents which can lead in turn to the pollution of freshwater and marine environments. The authors believe that many natural inexpensive materials, e.g. fungal biomass, and agricultural and animal waste, are able to play an important role in treatment processes of metal-contaminated waters. This study evaluates utility of some biological materials as biosorbents under known conditions (23 degree C), pH 5.2. The potential of these materials was compared with the efficiency of currency used sorbents, e.g. activated charcoal and ion-exchange resin. Ten of the tested materials showed a higher sorption capacity than that of activated charcoal and ion-exchange resin. The potential of various biological materials can be increased after alkaline treatment. The potential of fungal biomass and other biological materials, including local waste materials, which are inexpensive and easily available in the treatment of heavy-metal-contaminated waters, could make a significant contribution to the solution of important industrial and environmental problems, e.g. waste disposal.