Decolorization treatment method of dyeing wastewater colored with azo dye

摘要

PROBLEM TO BE SOLVED: To provide a colored wastewater treatment apparatus which makes colored wastewater colorless without increasing a COD value due to addition of bacteria to the wastewater treatment apparatus at the time of decolorizing colored wastewater contaminated with a dye using azo dye-decomposing microorganisms in the wastewater treatment apparatus.SOLUTION: A decolorization method of dye wastewater colored by an azo dye comprises: an azo dye-adsorbing step of adsorbing the azo dye by an adsorbent; an adsorbent recovery step of recovering the adsorbent having adsorbed the dye in the azo dye-adsorbing step; and an azo dye-decolorizing step of decolorizing the dye-adsorbed adsorbent, recovered by the adsorbent recovery step, by azoreductase of azo dye-decomposing microorganisms in a facultative anaerobic condition.