Remediation of 1,2,3-trichlorobenzene contaminated soil using a combined thermal desorption–molten salt oxidation reactor system

• Soil remediation using a TD–MSO system has not yet been widely used or analyzed.
• The chlorinated species were not detected in the emissions.
• The destruction mechanism and reaction pathway were proposed.

A combined thermal desorption (TD)–molten salt oxidation (MSO) reactor system was applied to remediate the 1,2,3-trichlorobenzene (1,2,3-TCB) contaminated soil. The TD reactor was used to enrich the contaminant from soil, and its dechlorination of the contaminant was achieved in the MSO reactor. The optimum operating conditions of TD, and the effects of MSO reactor temperatures, additive amounts of the TCB on destruction and removal efficiency (DRE) of TCB and chlorine retention efficiency (CRE) were investigated. The reaction mechanism and pathway were proposed as well. The combined system could remediate the contaminated soil at a large scale of concentration from 5 to 25 g kg−1, and the DRE and CRE reached more than 99% and 95%, respectively, at temperatures above 850 °C. The reaction emissions included C6H6, CH4, CO and CO2, and chlorinated species were not detected. It was found that a little increase in the temperature can considerably reduce the emission of C6H6, CH4, and CO, while the CO2 level increased.