Remediation of soil contaminated with tris-(1-chloro-2-propyl) phosphate using plant and microorganism combined technology: A greenhouse experiment.

The remediation of tris-(1-chloro-2-propyl) phosphate (TCIPP) -contaminated soil by the plant (ryegrass, Lolium perenne L.) and microorganism (TCIPP degrading bacteria, Ochrobactrum sp. DT-6) alone or in combination was investigated in this study. TCIPP can inhibit the growth and development of ryegrass and there is a clear dose-effect relationship. Inoculation with strain DT-6 was able to mitigate the toxic influence of TCIPP on ryegrass, but this mitigation effect was not significant. TCIPP in the soil was relatively easy to be uptaken by the ryegrass roots and migrated to the shoots. Furthermore, as the soil TCIPP concentration rose, the concentration of TCIPP in ryegrass also exhibited a corresponding increase. The biological concentration factor (BCF) ranged from 0.33 to 1.88 and the biological accumulation coefficient (BAC) ranged from 0.54 to 3.98. They all significantly decreased with higher soil TCIPP concentrations. The translocation factor (TF) values ranged from 1.55 to 2.34. Inoculation of strain DT-6 significantly reduced TCIPP concentrations in ryegrass roots, stems, and leaves as well as the values of BAC and BCF under low and medium TCIPP concentration treatment conditions, but the effect on TF values was not remarkable. The planting of ryegrass significantly raised the elimination of TCIPP from the soil to 64.6-93.3%, but the influence of inoculation with strain DT-6 on the remediation effect by ryegrass was not significant. The percentage contribution of phytoextraction to the elimination of TCIPP from soils ranged from only 0.64-5.23%.