COLD-CLIMATE CONSTRUCTED WETLANDS

This paper outlines design considerations for constructed wetlands wit h horizontal subsurface flow treating domestic wastewater in cold clim ates of northern latitudes. Particular attention is devoted to the use of a filter medium with high phosphorus adsorption capacity. Experien ce from two Norwegian multistage systems consisting of an aerobic pret reatment step followed by constructed wetland units indicates purifica tion processes are nearly the same during winter and summer seasons, w ith quite high removal of organic matter (COD, BOD), phosphorus and ni trogen.