METHOD FOR CLEANING SEPARATION MEMBRANE

摘要

PROBLEM TO BE SOLVED: To provide a treating technique to concentrate the un-adsorbed dyestuff-containing liquid waste generated at the final dyeing step by using a separation membrane, to recover the separated water and to reuse the recovered water. SOLUTION: This separation membrane cleaning method comprises a step to separate a spent solvent generated at the final fiber dyeing step into a spent fiber treating chemical and a solvent and regenerate the separated solvent by using the separation membrane. The spent solvent containing at least the precipitating component of the fiber treating chemical having 0.01-100μm particle size is separated and regenerated to obtain a regenerated solvent. In this are thud, the solvent is separated and regenerated and the element of the separation membrane is cleaned by fluidizing the spent solvent on the surface layer of the separation membrane to the gravitating direction in a condition on of Fc/Fp>1 (wherein Fc is the flow rate of the concentrated liquid of the spent fiber treating chemical; Fp is the flow rate of the solvent to be regenerated).