1. Department of Sanitary and Environmental Engineering, Federal University of Minas Gerais, PO Box 1294, ZIP 30.270-901, Belo Horizonte, MG, Brazil
2. Chemistry Department, Federal Center of Technological Education of Minas Gerais, ZIP 30421-169, Belo Horizonte, MG, Brazil
3. PAM Membranas Seletivas (PAM Selective Membranes), Rio de Janeiro, RJ, Brazil