BIOLOGICAL SULFIDE PRESTRIPPING FOR METAL AND COD REMOVAL

Organic wastes of high concentration and containing high concentrations of metals have generally been treated by a preliminary metal removal process (for example, precipitation) followed by biological treatment of the degradable component of the organic matter. It was the objective of this study to determine if a high strength waste containing metals could be treated by a precipitation-anaerobic digestion process in which the precipitant was sulfide generated by the digestion step itself. To answer these questions, laboratory reactors were fed a synthetic medium (containing copper as the metal of interest and glucose and acetate as primary organic substrates) and operated in a semicontinuous draw and fill manner. Overall, the results of this study are encouraging and point to the potential feasibility of the process.