Retracted: Purification Effect of Plants on COD, DO from Domestic Sewage in Jilin City"

The purification efficiency of chemical oxygen demand(COD) and the change of dissolved oxygen (DO) of domestic sewage was researched by testing 9 species of wetland plants along the Songhua River in Jilin City in this paper. It is shown that 9 species of plants can purify domestic sewage, and the purification ability is varied in different species. Polygonum persicaria L., Rudbeckia hybrida Hort. have better comprehensive capacity for domestic sewage purification of removal of chemical oxygen demand and increase of dissolved oxygen; and used the 9 species of plants for the construction of domestic sewage purification landscape.