1. Dep. of Biosystems Engineering, Faculty of Science and Technology; Aarhus Univ.; Blichers Allé 20 8830 Tjele Denmark
2. Center for Chemistry and Water Technology; Danish Technological Institute; Kongsvang Allé 29 8000 Aarhus Denmark
3. Agrotech-Institute for Agri Technology and Food Innovation; Udkaersvej 15 8200 Aarhus N Denmark