Study On Lake Water Purification By Artificial Wetland

Lake is one of the important fresh water resources, which have tight relationship with the sustainable economic development and the people's lives. In recent years, we have great economic benefits from the lake, but we also bring serious damage to the ecosystem of the lake. This paper discusses the effect of artificial wetland to contaminated lake water purification, in the basis of the construction of simulant artificial wetland. The conclusions are as following:(1) Artificial wetland had a good effect to contaminated lake water purification, which made the lake water quality to improve to some extent. The COD, TN, TP of contaminated lake water were improved 1~2 grades after we assayed and compared the quality of raw water and effluent water.(2) Hydraulic loading rate is a significant parameter of the treatment efficiency. The capability of constructed artificial wetland was proposed by the removal rate and unit area elimination quantity, which was assayed in two devices running at the same time, on four different hydraulic loading rate. As an index of the purifying effect of COD, TN, TP, the best hydraulic loading was 0.8m3/m2/d, in the second model planting iris.(3) Cyperus alternifolius was less cold-resistant, which died easily in low temperature in the south area, Iris was better cold-resistant than Cyperus alternifolius, the purification ability of which was also better.(4) We clearly found that filler adding activated carbon acts the better treatment efficiency.(5) Double-layer composite filler was used in the experiment. Layered sampling shows that, COD removal mainly acts in the upper filler with plant roots, TN, TP removal mainly acts in the lower filler.