METHOD FOR REUSE OF DYE RESIDUAL LIQUID AND RECLAMATION METHOD OF DYE REMOVER

摘要

PROBLEM TO BE SOLVED: To provide a method for reusing a residual liquid in dyeing and a method for regenerating a dye remover which enable dyes to conveniently be removed from the residual liquid in dyeing in a dyeing process, thereby enable the residual liquid to be used cyclically in order to reduce costs necessary for the treatment of wastewater containing a large quantity of dyes and a dye-assist agent, decrease the influence on surroundings and moreover efficiently use useful materials such as water resources and sodium sulfate. SOLUTION: This method for reusing a residual liquid in dyeing comprises the following processes: (1) bringing the residual liquid in dyeing which has been discharged from a dyeing process and contains dyes and a dye-assist agent into contact with a condensation product of glycoluril with formaldehyde to take up the dyes in the condensation product; (2) separating from treated water the condensation product which has taken up the dyes; and (3) returning the decolored treated water to the dyeing process. This method for regenerating the condensation product of glycoluril with formaldehyde comprises bringing the condensation product which has taken up the dyes into contact with the 0.0001-0.1 N aqueous solution of a specific water-soluble organic solvent and/or a specific alkali compound to remove the dyes from the condensation product.