Obtenção de membranas cerâmicas utilizando matérias-primas regionais e alternativas para uso em tratamento de água.

Abstract

Separation processes involving ceramic membranes have shown high potential for applications in various industrial sectors. The main reasons for the advancement of these separation technologies are the fact that these membranes work without the addition of chemical agents and require low energy. Currently, the main concern in their development is to minimize costs and achieve more efficient production processes. The aim of this study was to evaluate the ceramic membrane properties obtained with regional and alternatives raw materials aimed at use in water treatment. Therefore, compositions were formulated using the mixture design of clay, granite waste and porogenic agents. As porogenic were used sucrose, calcite and shellfish shells powder. The clay, granite waste, calcite and shellfish shells powder were subjected to physical and mineralogical characterization. Membranes were shaped in the form of discs via uniaxial pressing process and heat treated at temperatures of 900, 1000 and 1100 ° C and after the samples were analysed by characteristics of porosity, strength and microstructural aspects. Distilled water flow tests were conducted / permeability and porosimetry by mercury intrusion and, from these results, the most promising membranes for testing were selected with a view to the application of the same at treating a water supply system Campina Grande city, PB. The best results were obtained with membranes made by the compositions clay, sucrose and shellfish shells powder, reaching varying porosity in the range from 37.53 to 46.70% with an average pore diameter varying from 0.0038 to 0,2206 μm, diametrical compression strength of 1.93 5,39 MPa and the permeability flux (using distilled water) of about 500 l / h.m2. These membranes were sorted for possible applications in microfiltration, ultrafiltration and nanofiltration, and were effective in the treatment of water, with the removal of 100% of the color, turbidity, solids suspensions and significantly reduce the concentration of hardness, alkalinity, total acidity and chloride.