Combined remediation of PCBs polluted soil by plant and microorganism in a field trial

The remediation of polychlorinated biphenyls(PCBs) contaminated soil by inoculation with arbuscular mycorrhizal fungus(AM,Glomus versiforme) and/or rhizobium(Rhizobium meliloti) with a host plant(Medicago sativa L.) was studied in a field trial. Concentrations of PCBs decreased at a higher rate in all soils with this planted treatment compared with untreated soils. The planted treatment that received the rhizobial inoculum decreased the concentration of PCBs by 42.6%,which was significantly higher than the other treatments. Analysis of PCBs composition showed that the percentage of lower chlorinated PCBs increased in all of the planted treatments,especially the plant treatment with rhizobium. Rhizobium could promote the growth of the plant and even facilitate the absorbability and the transportation of the PCBs in the plant. The field trial showed that the plant with rhizobium could be used to remediate soils contaminated with PCBs.