| 摘要 |
PURPOSE:To easily and perfectly perform decoloration, by treating a washing solution containing a specific colorant after use with a chlorine type decolorant to perform the decoloration thereof. CONSTITUTION:In the treatment of a colored washing solution containing a colorant represented by formula [wherein A and B are respectively independently an aromatic group bonded to a carbonyl group and Y or Z in a form selected from an 1,2-phenylene group or an 1,8-naphthylene group, Y and Z are respectively independently a group consisting of NH and S, -SO3M is an alkali metal sulfonate group on A and/or B and(m) is 1-4], chlorine gas or an aqueous hypochlorite solution is added to the washing solution after use to perform decoloration treatment. Decoloration can be also performed by microbial treatment according to an activated sludge method. |
