BIOLOGICAL ACTIVATED CARBON TREATMENT OF EFFLUENT WATER FROM WASTE-WATER TREATMENT PROCESSES OF PLATING INDUSTRIES

Biological activated carbon treatment is applied to a type of wastewat er collected from plating industries. The water contains small amounts of refractory organic pollutants, such as anionic surfactants, small amounts of heavy metals, such as cupric and chromic ions, and large am ounts of sodium salts. It is found that the thickness of biofilm forme d around activated carbon particles increases with time, even though t he existence of heavy metals is unfavorable to the growth of microorga nisms. As a result, about 50% of organic substances are removed from t he water. Present removals for the ionic species of copper and chromiu m are about 80% and 30%, respectively. Heavy metals are removed from t he wastewater by uptake in the bodies of microorganisms, while organic substances are removed by biological decomposition and partly by adso rption.