1. ETH Zürich; Institute of Environmental Engineering; Zürich 8093 Switzerland
2. Eawag-Swiss Federal Institute of Aquatic Science and Technology; Dübendorf 8600 Switzerland
3. School of Architecture; Civil and Environmental Engineering, Ecole Polytechnique Fédérale de Lausanne; Lausanne 1015 Switzerland
4. Department of Biotechnology; Delft University of Technology; Delft 2629 HZ The Netherlands