Apparatus and method for treating waste water containing organic substances

The present invention provides a treatment apparatus of organic-containing effluent and treatment method, which can complete effectively decompose the organic-containing effluent. The present invention relates a treatment method of organic-containing effluent comprising: a dissolved oxygen apparatus after once-treatment using electrolysis treatment and/or agglutination treatment to treat the organism which is hard to be decomposed in the effluent; an organic-containing apparatus with fluid type bioreactor for treating the effluent approach to saturating condition of dissolved oxygen provided from the said dissolved apparatus; then once-treatment effluent was once-treated by the electrolysis treatment and/or agglutination treatment and the dissolved oxygen amount of the effluent was treated by the dissolved oxygen apparatus to closely achieve the saturating condition. Consequently, the effluent which approaches to the saturating condition of the dissolved oxygen was applied to the fluid type bioreactor in order to take the microorganism-treatment place.