1. Department of Environmental and Resource Engineering, Technical University of Denmark. Bygningstorvet, 115, Kgs. Lyngby 2800, Denmark
2. Infrastructure and Environment, School of Engineering, University of Glasgow, University Avenue, Glasgow G12 8QQ, U.K.
3. Assens Forsyning A/S, Forsyningsparken 2, Assens 5610, Denmark
4. Center for Water Technology (WATEC), Department of Biological and Chemical Engineering, Ole Worms Alle 3, Aarhus University, Aarhus C 8000, Denmark