Abstract: In order to study the distribution characteristics of Cr and Cu in the artificial wetland matrix, the 5th series in the Soap River artificial wetland demonstration project was selected as the research object, 11 sampling points were set along the water flow direction, and 3 sampling points at different depths were set at 7 sampling points. The spatial distribution characteristics of the total amount of heavy metals and the content of each form were analyzed, and the results showed that the trend of the total Cr and Cu content in the horizontal direction was similar along the course, with a significant decrease in sampling points 1 to 8 and a slight increase in sampling points 9, 10 and 11; in the vertical direction, the total amount of Cr and Cu decreased along the depth; the main distribution form of Cr and Cu in the wetland surface matrix was the residue state. The distribution trend of the size of Cr and Cu in the wetland surface matrix is basically the same, and the total size of the four forms showed residue state > reducible state > oxidizable state > weakly acid soluble state; the contents of Cr and Cu in the weakly acid soluble, reducible and oxidizable states decreased continuously with depth.

Key words: wetland, heavy metal, matrix