1. Swiss Federal Institute for Environmental Science and Technology (EAWAG) and Swiss Federal Institute of Technology (ETH), Ueberlandstrasse 133, CH-8600 Duebendorf, Switzerland (telephone:+41 1 823 5076; fax: +41 1 823 5210; email: Torsten.schmidt@eawag.ch)
2. Department of Civil and Environmental Engineering and Department ofc Animal Sciences, University of Illinois at Urbana-Champaign, 205 North Mathews Avenue, Urbana, IL 61801
3. UFZ Centre for Environmental Research Leipzig-Halle, Interdisciplinary Department of Industrial and Mining Landscapes, Permoserstrasse 15, 04318Leipzig, Germany