In Norway systems consisting of an aerobic biofilter followed by a subsurface horizontal flow constructed wetland have been very successful in reducing organic matter, indicator bacteria, nitrogen and phosphorus in greywater. This paper describes design details and performance of biofilter/constructed wetland systems for greywater treatment in cold climates.
JENSSEN, P.D. VRALE, L. (2004): Greywater Treatment in Combined Biofilter/Constructed Wetlands in Cold Climate. In: WERNER, C. (2004): Ecosan - Closing the Loop. Lübeck, Germany: 875-881. URL [Accessed: 21.11.2012]