Abstract: The phytoremediation potential ofEchinacea purpurea on PAHs heavily contaminated soils was investigated with pot experiment. The polluted soils were collected from an oil field. Two types of soils with different concentrations of PAHs (122.40 and 183.60 mg·kg^-1) were prepared by adding a given proportion of polluted soil, non-polluted soil, sandy soil, and PAHs multicompound standards. The height and biomass ofE. purpurea, and the removal rate of four kinds of PAHs, pyrene(Pyr), chrysene (CHR), benzo(b)fluoranthene (BbF), benzo(k)fluoranthene (BkF), were measured. The results showed that: (1) The height and biomass were significantly inhibited by PAHs, but E. purpurea still could survive with the total PAHsconcentration at 183.60 mg·kg^-1. (2) The removal rates of Pyr, CHR, BbF and BkF were 66.2%, 70.3%, 40.6% and 65.4%, respectively. The total PAHs decreased from 183.60 mg·kg^-1 to 104.52 mg·kg^-1. The total removal rate of four kinds of PAHs was 56.93%, which was much higher than that in the control. This result demonstrated thatE. purpurea has a good potential for phytoremediation of heavily PAHs contaminated soils. The significant correlation between theremoval rate of PAHs and belowground biomass indicated that the belowground biomass of plants had a greater influence on the removal rate of PAHs. This study expanded the application range of phytoremediation on PAHs contaminated soils.

Key words: ecosystem service, trade-off and synergy, Poyang Lake region, land use