Enhanced dissipation of PAHs in soils by mixed cropping

摘要

The plant-promoted removal of polycyclic aromatic hydrocarbons (PAHs) in soils ranging from 20.08 to 322.12 mg·kg~(-1) was investigated under different planting patterns, and enhancement mechanisms were analyzed. Results showed that the dissipation of PAHs (68.22%~75.06%) in soils growing Brassica campestris and Trifolium repens significantly exceeded those (40.38%~43.26%) vegetating single species. After 80 days plantation, the extractable PAHs in soils under mixed cropping were much lower than those under single cropping. Despite the presence of vegetation evidently enhanced PAHs removal, the plant-microbial interactions are the main pathway for dissipation of pollutions under mixed cropping mode. These results suggested a feasibility of the establishment of multi-species phytoremediation for improvement of the remediation efficiencies of PAHs, which may decrease accumulations of PAHs in crops and thus reduce their risks.