Abstract
Compact wetland was developed using subsurface flow (SF) and more porous artificial filling. This paper mentions comparison of three experimental wetlands, which are a free-water-surface wetland (FWS), SF wetland with gravel filling and SF wetland with artificial filling. Each wetland has an area of 50m2. Two kinds of SF wetlands purify water better than FWS wetland, however there is not obvious difference between two kinds of SF wetlands with gravel and artificial fillings. Two SF wetlands are able to remove nitrate nitrogen efficiently with a removal ratio of 66 to 77 percentage under the condition of water temperature is less 15 degree Celsius and dissolved oxygen is less than 3mg/l.
