Impact of Four Plant Species and Arbuscular Mycorrhizal (AM) Fungi on Polycyclic Aromatic Hydrocarbon (PAH) Dissipation in Spiked Soil

Alfalfa, tall fescue, ryegrass, and celery, some of which were inoculated with the AM fungus Glomus intraradices, were compared for their contributions to phenanthrene (PHE), pyrene (PYR), and dibenzo(a,h)anthracene (DBA) dissipation in spiked soil. A pot experiment was conducted in which PAHs extracted from soil and plant, quantity of PAH degraders, and plant biomass were evaluated. The results showed that biodegradation was the dominant removal mechanism for PAHs from soil while PAH accumulation in the plant tissue was negligible. PAH dissipation varied with the plant species and decreased with the increase of PAH molecular weight. The four plant species displayed a positive effect on PHE dissipation, and alfalfa improved PYR and DBA dissipation. AM fungi significantly increased plant biomass, phosphorus uptake, and PHE removal rate in planted treatments. Plant biomass and PAH degraders showed a weak linear relationship with PAH dissipation, indicating that there might be other important factors influencing PAH dissipation.