TREATMENT OF ORGANIC WASTE WATER

摘要

PURPOSE:To stabilize treatment capacity by controlling the circulation ratio of treated water on the basis of the concn. of dissolved oxygen in treated water or a liquid mixture and the concn. of gaseous phase oxygen in an oxygen dissolving tank in an aerobic ascending current type sludge bed method. CONSTITUTION:In an aerobic ascending current type sludge bed method wherein a liquid mixture of org. waste water to be treated in which oxygen is preliminarily dissolved in an oxygen dissolving tank and circulated treated water is passed upwardly through a biological treatment tank having a mixed bacteria bed becoming granular by self-flocculation force present therein and org. waste water is treated without destroying granular matter, the circulation ratio of treated water is controlled on the basis of the concn. of dissolved oxygen in treated water or the liquid mixture and that of gaseous phase of the oxygen dissolving tank or the concns. of dissolved oxygen in treated water and the liquid mixture or the concn. of dissolved oxygen in treated water and that of gaseous phase oxygen in the oxygen dissolving tank. By this method, the stabilization of the treatment capacity of the aerobic ascending current type sludge bed method and the reduction of operation cost due to the rationalization of an oxygen use amount become possible.