Combining remediation techniques increases kinetics for removal of persistent organic contaminants from soil

A number of techniques, both mechanical and biological, have been investigated for the remediation of persistent organic contaminants from soils. However, most of these techniques have been applied independently. As a consequence of using only one process, remediation usually is slow for persistent organic contaminants. To improve remediation, multiple techniques that complement different aspects of contaminant removal have been applied to soils in combination. This resulted in an enhanced multi-process phytoremediation system that improved and accelerated the overall remediation resulting in removal of 95% of total PAHs. The remediation system includes physical (volatilization), photochemical (photooxidation), microbial degradation and plant growth (phytoremediation) processes. The techniques applied to realize these processes are land farming (aeration and light exposure), microbial remediation (introduction of contaminant degrading bacteria) and phytoremediation (plant growth with plant growth promoting rhizobacteria). This system was very effective at removal of persistent, strongly bound contaminants from soil. It appears that the combination of these components may be a viable solution for remediating persistent organic contaminants from soils.