Thermal remediation of PCDD/Fs contaminated soil by zone combustion process.

A new thermal process has been proposed for remediating soils contaminated by chlorinated organic compounds, e.g., PCDD/Fs and PCBs. This is to apply the "zone combustion process" which utilizes stable combustion of coke particles in the packed bed to soils with air flow across the bed. The usefulness and validity were obtained the results showing that more than 98.9% of PCDD/Fs in the soil was successfully removed in a laboratory-scale experiment. Some pretreatment of the soil sample, such as drying, pre-granulation and addition of limestone was found to make the removal efficiency better. Although, some fundamentals on the behavior of PCDD/Fs, e.g., decomposition/vaporization ratios and formation of other compounds cannot be certainly identified yet, the present results clearly show a way to remediate the contaminated soils and solid wastes.