Low temperature thermal desorption-chemical oxidation hybrid process for the remediation of organic contaminated model soil: A case study

Abstract

The efficiencies of thermal desorption and oxidation process in engineering soil remediation are to some extent limited due to the huge loss of heat to the soil or underground water or mass transfer resistance in the soil. To enhance the oxidation and improve the energy utilization. Herein, the thermal desorption process and the oxidation process (by ozone) are combined together to remediate the organic contaminated model soil (take the 2,4-dimethylaniline (2,4-DMA) as pollutant). Results show that this hybrid process could not only reduce the thermal desorption temperature (as low as 50–90 °C), but also improve the oxidation efficiency significantly, even achieving 100% degradation of 2,4-DMA in less than 10 min in the soil. It is found that the remediation efficiency by the hybrid process is also highly dependent on different operational parameters, including the heating temperature, ozone concentration, especially the moisture content in the soil. The results suggest that a proper content of water in the soil is beneficial for the degradation of pollutants by the hybrid process. Finally, the degradation kinetics and mechanisms of 2,4-DMA in the soil by the hybrid process has been primarily discussed. These findings suggest that the low temperature enhanced chemical oxidation process would be a promising method for future remediation of organic contaminated soil due to its relatively low energy consuming and high removal efficiency in shorter time.