Removal of Direct Blue Dye from Aqueous Solution Using New Polyurethane - Cellulose Acetate Blend Micro-filtration Membrane

1075 * email: icre@ch.tuiasi.ro Worldwide there are over 100 000 dyes commercially used and annually there are produced more than 7·105 tones of dyes. From the ecological point of view, the waste waters that come from the industries which are using dyes represent a problem because these dyes have carcinogen, teratogen and mutagen effects [1]. Also, the effluents from these industries are aesthetically displeasing because the water is highly colored. Disposal of this colored water into receiving water can be toxic to aquatic life [2,3]. The dyebased effluents are considered a very complex mixture of many polluting substances from pesticide to heavy metals, which are non-biodegradable and persistent. Moreover, dyes can be accumulated in sediment and soil, especially in locations of wastewater discharge, creating very serious environmental problems [3-9]. The treatment of these wastewaters is a major problem for the textile industry. For this purpose, biological and physico-chemical methods are being used. The physicochemical processes include electro-flotation, flocculation, electro-kinetic coagulation, precipitation, ion exchange, irradiation, electrochemical destruction, ozonation and membrane filtration. Biological methods include aerobic and anaerobic digestions use microorganisms [2, 4-6]. One of the most effective and economical methods used in removal of toxic metal ions and dissolved organic compounds, is micellar-enhanced ultrafiltration (MEUF). This method was introduced in 1980 for the removal of copper ions from wastewaters [10]. Micellar-enhanced ultrafiltration (MEUF) is a surfactant based separation process. In the MEUF process, the surfactant is added to the polluted aqueous solution containing metal ions and/ or organic solutes [1, 3, 11-16]. When the surfactants are added to the contaminated solution, at levels near critical micellar concentration (CMCs), surfactant monomers will Removal of Direct Blue Dye from Aqueous Solution Using New Polyurethane Cellulose Acetate Blend Micro-filtration Membrane