Low temperature thermal degradation of PCDD/Fs in soil using nanosized particles of zerovalent iron and CaO

This study investigated the degradation of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in contaminated soil using low temperature treatment (200-280 degrees C) both alone and in combination with nanosized zerovalent iron (nZVI) particles or CaO. Control soil samples and soil fortified with nZVI particles or CaO were treated at 200 and 250 degrees C in sealed glass ampoules. Treatment of the ampouled samples at 250 degrees C was more effective than treatment at 200 degrees C and the reduction in PCDD/F concentration was greatest when soil was treated at 250 degrees C with nZVI addition (indeed, treatment at 200 degrees C in the absence of nZVI resulted in increases in total PCDD and PCDD/F concentrations). In larger-scale experiments based on the obtained results, using a rotary furnace, the greatest reduction in total PCDD/F concentration was achieved by treating soil at 280 degrees C, and adding nZVI to the soil resulted in almost no detectable PCDD/F in the gas phase. (C) 2013 Elsevier Ltd. All rights reserved.