1. Department of Chemical and Environmental Process Engineering, Budapest University of Technology and Economics, 1111Budapest, Hungary
2. Chemical Engineering Division, Kenya Industrial Research and Development Institute, P.O. Box 30650, 00100Nairobi, Kenya
3. Department of Environmental and Resource Engineering, Technical University of Denmark, 2800Kgs. Lyngby, Denmark
4. Department of Fine Chemicals and Environmental Technology, University of Miskolc, 3515Miskolc, Hungary