1. Dep. of Biotechnology, Chemistry and Environmental Engineering; Aalborg Univ.; Sohngaardsholmsvej 57 DK-9000 Aalborg Denmark
2. Dep. of Agroecology and Environment, Faculty of Agricultural Sciences; Aarhus Univ.; Blichers Allé 20, P.O. Box 50 DK-8830 Tjele Denmark
3. Dep. of Civil and Environmental Engineering; Graduate School of Science and Engineering, Saitama Univ.; 255 Shimo-okubo, Sakura-ku Saitama 338-8570 Japan