EFFECT OF 2-STAGE TREATMENT ON THE BIOLOGICAL TREATABILITY OF STRONG INDUSTRIAL-WASTES

Some agro-industries generate wastewaters with very high COD concentra tions and require two-stage biological treatment. Inert or residual or ganic constituents of these wastewaters, even at very low ratios, play a major role in the compliance of effluent standards. In this study, two strong wastes, citric acid plant effluent and cheese whey were tes ted for their inert COD content. The experiments showed that the first -phase anaerobic treatment provided a major decrease in the residual C OD, but introduced significant amounts of particulate residual COD to the second phase. A newly developed procedure was used for the assessm ent of the soluble and particulate residual COD.