Desenvolvimento de membranas assimétricas de alumina para pré-tratamento de água

Abstract

The growing worldwide concern with environmental preservation has forced changes in industrial waste management, promoting the search for new technologies of waste treatment. Increasingly in evidence due to their energetic efficiency and ease of use are the processes that have membranes in the active functional role. Ceramic membranes are deemed superior relative to polymeric ones in the areas of thermal, chemical and mechanical stability as well as resistance to tear and wear. In this context, the present study aims the development of asymmetrical tubular alumina ceramic membranes for evaluation of their applicability in water pretreatment. To this end, asymmetrical tubular ceramic membranes were produced using Brazilian aluminas, with distinct characteristics, and one synthetic effluent to evaluate their performance. The characterization of the membranes was made using electronical microscopic scanning, mercury porosimetry, thermogravimetric analysis and X-ray diffraction techniques, and their viability tested using laboratorial flow and rejection measurements for water pretreatment. The results showed that: a) Brazilian alumina evinced adequate characteristics for production of asymmetrical ceramic membranes; b) all membranes were efficient in the treatment of the synthetic effluent, reducing turbidity values to near zero; and c) the “C” membrane, with lesser width of the active layer and greater uniformity, evinced the best performance of all membranes in the study, combining high efficiency and permeability.