Poly(acrylonitrile-co-sodium styrenesulfonate) copolymers of various co-monomer sodium styrenesulfonate compositions, labelled AS1 and AS3, were synthesized by radical polymerisation in solution. The poly(acrylonitrile)-based materials and polysulfone-based materials, modified by poly(sodium 4-styrenesulfonate), labelled PS-S1 and PS-S3, were used to prepare ultrafiltration membranes by phase-inversion method. AS1 and AS3 copolymers, and PS-S1 and PS-S3 blends were characterized by means of Fourier transform infrared (FTIR) and thermogravimetric analysis (TGA) methods. Filtration properties of the membranes were, then, studied. For this purpose, aqueous solutions of carboxymethylcellulose, acting as synthetic textile sizing agent, were ultrafiltered through the studied membranes. Water permeability was investigated before and after ultrafiltration of the macromolecular solutions and the solvent flux variations made it possible to investigate the effect of the macromolecular solutes on the permeability of the studied membranes. The paper outlines, particularly, the resistance to irreversible fouling of the AS1 membrane. Thus, its anti-fouling capabilities combined with good rejection of carboxymethylcellulose macromolecular solute allow to predict promising aptitudes for the AS1 membrane in the treatment of desizing wastes.