Desenvolvimento de membranas cerâmicas tubulares com resíduo de granito para separação de índigo em efluente da indústria têxtil.

Abstract

Membranes are classificad as semipermeable, which under certain driving force, allows the preferential passage of one or more species or components present in a solution. Ceramic membranes can be used in environments with a wide range of pH and in the presence of various organic solvents, thus expanding its scope of application. Because they are immune to biological attack, minimizes the possibility that micro-organisms become encrustated and multiply on the membrane surface during the separation process. The development of membranes incorpored with waste is recent and still very low. The objective of this work was the development of tubular ceramic membranes with granite waste in two different compositions to be tested in the separation of indigo in textile industry effluent. First the raw materials were characterized physically and mineralogically by laser particle size analysis, chemical analysis (EDX), X-ray diffraction (XRD), thermogravimetric analysis (TG) and diferencial thermal analysis (DTA). The membranes were made of bentonitaclay, granite waste and quartz, were processed by extrusion and fired at 750, 800, 850 and 900 º C and then characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), porosimetry mercury intrusion analysis and tangential flow with deionized water. It was performed a preliminary study where the membranes were tested with indigo solution simulating the textile industry effluent. Finally the membranes showed better performance were tested with real indigo in effluent flow tangency. The membranes showed equivalent average pore diameter between 0.06m at 0.60m porosity close to 29%. Deionized water flows increased with increasing the equivalent pore diameter and the pressure through membranes. The membranes were effective in retaining indigo, although it was observed a degrease in the permeate flow we to the fooling by indigo blue molecule un the membrane surface.