Abstract: Based on the water quality of landfill leachate tail water of the Laogang Garbage Landfill in Shanghai, the purification effect to TN, TP and COD in the tail water and biomass changes of three emerged plants Acorus calamus, Iris pseudacorus and Thalia dealbata in different configuration modes under hydrostatic conditions were investigated. Results showed that the purification effect to TN, TP of leachate tail water was distinct, the removal rate being over 75.1%, while the COD removal rate belows 62.8%. TN, TP purification effect of the three plant mixed mode was superior to that of the two mixed modes and the single plant mode; but there are no significant differences to COD removal rate among different modes. It is necessary to consider the actual conditions to select suitable plant configuration mode to ensure more effective purification efficiency because the purification effect is closely related to plant biomass, enrichment of unit volume, and different cooperative purification between plants in purifying water body.

Key words: aquatic plants, configuration mode, landfill leachate tail water, purification