Here I present some good realizations of wetland systems build in the cold Hokkaido island in Japan where Winter time is severe. My dear friend Kunihiko Kato, researcher at National Agricultural Research Center for Hokkaido Region (Japan) design six treatment wetlands for animal wastewater (pigs, dairy milking parlour) and agroindusty (potato starch processing). The photos below show the plants before and after plants growing, how they are integrated in the environment and a spectacular image under snow.
Dr. Kato follow by chemical analysis the performance of all the plants and they are very good, with an average reduction of 80% for total phosphorus, 90 % for COD, 80 % for total nitrogen. Congratulation Kunihiko.