Potential of arsenate-reducing bacterial inoculants to enhance field-scale remediation of arsenic contaminated soils by Pteris vittata L

The effects of arsenate-reducing bacterial inoculants (C13, F2, F2-As and compound microbial inoculant) on the remediation of arsenic (As) contaminated soil by Pteris vittata L. were studied in field experiments. The results showed that the application of F2, F2-As and the compound microbial inoculant significantly promoted plant growth, increased the As accumulation of P. vittata, and improved soil As removal efficiency. When compared with the uninoculated treatment, the frond biomass and As accumulation of P. vittata increased by 14.89% -50.98% and26.83%-54.26%, respectively, and the As removal rate increased by 0.55%-3.82%. The combination of the F2-As inoculant and P. vittata showed the highest remediation efficiency with the As removal rate reaching 6.66% during the 3-month experimental period. Application of arsenate-reducing bacterial inoculants increased the dissolved organic carbon content and available As content in rhizosphere soil of P. vittata by 15.67%-20.39% and 22.49%-44.09%, respectively, indicating that arsenate-reducing bacterial inoculants could modify As bioavailability and therefore might be beneficial for plant As accumulation. The results reveal that arsenate-reducing bacterial inoculants can improve the remediation efficiency of P. vittata, and can be exploited as a promising strategy for As contamination remediation.