DECOLORIZATION OF DYE SOLUTIONS BY CONTINUOUS ULTRAFILTRATION

A method of decolorizing and concentrating aqueous solutions of organic dyes in an ultrafiltration process is described. The process involved polysulfone membranes prepared from 15% (wt. %) polysulfone solution in dimethylformamide and formed on a glass support. The experiments were carried out under static and dynamic conditions for five organic dyes of a molecular weight ranging from 327 to 1048. 2. The pressure applied was 1. 5 MPa. Membranes exhibiting the best properties are capable of retaining 90 to 100% of orgnic dyes of a molecular weight above 700 during their work under dynamic conditions. The measured volume fluxes through these membranes ranged from 0. 08 to 0. 18 m**3/m**2 day.