Enhanced dissipation of PAHs in soils by combined plants cultivation

摘要

Dissipation of polycyclic aromatic hydrocarbons (PAHs) in soils at initial concentrations ranging from 20.04 to 322.06 mg·kg~(-1) was investigated when planting single or mixed species, and enhancing mechanisms were analyzed. Results showed removal of PAHs in soils growing Brassica campestris and Medicago sativa significantly exceeded those vegetating single species. During 70-day experiment, about 75.06% of phenanthrene(Phe) and 68.22% of pyrene(Pyr) was removed from soils under mixed cropping; while only 31.8% and 64.03% of Phe and 27.84% and 51.93 of Pyr were removed under single rape or alfalfa cropping, respectively. Of all pathways enforcing PAHs removal, plant-microbial interactions is the most predominant. These results suggested a feasibility of the establishment of multi-species phytoremediation for improvement of remediation efficiencies of PAHs, which may decrease accumulations of PAHs in crops and thus reduce their risks.