Development of a new styrene copolymer membrane for recycling of polyester fibre dyeing effluent

A new ultra-filtration membrane has been developed using indigenously available polymer, low cost solvents and a simple casting technique. The performance evaluation of the developed membrane in terms of pure water permeability (PWP), flux and rejection as compared to commercially available national and international membranes was carried out. It is observed that the newly developed membranes show acceptable performance both in terms of flux and rejection. The compressibility characteristic of the new membrane shows an improvement after suitable chemical modification through cross-linking reactions, The application perspectives of the membranes developed in our laboratory have been evaluated for the selective separation of dyes from typical textile waste stream of polyester fibre dyeing units with an aim to recover and recirculate the auxiliary chemicals and water in the process house. The rejection of dyes >98% and the permeate flux (0.8-1.0 m(3)/m(2) per day) values obtained for a specific type of textile effluent is of acceptable standards. The membranes were characterised for pore size and pore size distribution using molecular weight cut-off, combined bubble pressure and solvent permeability method, Membrane morphology has been studied using scanning electron microscopy (SEM). The other features of the developed membrane are its resistance to temperature and adverse chemical environment. (C) 2001 Elsevier Science B.V. All rights reserved.