1. Program
of Environmental Engineering, Faculty of Engineering, University of Medellin, Carrera 87 No. 30-65, Medellin, Colombia
2. Department
of Chemical Engineering, University of the Basque Country, P.O. Box 644, E48080 Bilbao, Spain
3. Deparment
of Chemical, Biological Engineering, University of British Columbia, 2360 East Mall, Vancouver, British Columbia V6T 1Z3, Canada