Remediation of hydrocarbon-contaminated soils byex situmicrowave treatment: technical, energy and economic considerations

Abstract

In this study, the remediation of diesel-polluted soils was investigated by simulating an ex situ microwave (MW) heating treatment under different conditions, including soil moisture, operating power and heating duration. Based on experimental data, a technical, energy and economic assessment for the optimization of full-scale remediation activities was carried out. Main results show that the operating power applied significantly influences the contaminant removal kinetics and the moisture content in soil has a major effect on the final temperature reachable during MW heating. The first-order kinetic model showed an excellent correlation (r2 > 0.976) with the experimental data for residual concentration at all operating powers and for all soil moistures tested. Excellent contaminant removal values up to 94.8% were observed for wet soils at power higher than 600 W for heating duration longer than 30 min. The use of MW heating with respect to a conventional ex situ thermal desorption treatment could significantly decrease the energy consumption needed for the removal of hydrocarbon contaminants from soils. Therefore, the MW treatment could represent a suitable cost-effective alternative to the conventional thermal treatment for the remediation of hydrocarbon-polluted soil.

Lab-scale investigation on remediation of diesel-contaminated aquifer using microwave energy

“…In fact, MW heating is based on the direct interaction of the microwave with the contaminated matrix. This consequently allows conventional heating limitations to be overcome, which in turn leads to a reduction of treatment time, risk of further contamination and costs (Falciglia and Vagliasindi, 2014).…”

Thermal desorption treatment of petroleum hydrocarbon-contaminated soils of tundra, taiga, and forest steppe landscapes

“…Application of bioremediation approaches is another option, e.g., by stimulating indigenous microbes, plant-bacteria partnerships, and biodegradation by a microbial consortium or by natural attenuation, biostimulation, and bioaugmentation (Bento et al 2005 ; Ghazali et al 2004 ; Khan et al 2013 ; Liu et al 2010 ). Application of chemicals is fraught with challenges and further environmental concerns, while biotechnologies are eco-friendly but slow-acting; it is against this background that we used the thermal desorption as the main mechanism for cleaning soils from petroleum products (Falciglia et al 2011 , 2013 , 2014 ; Jia et al 2020 ; Kang et al 2020 ; Li et al 2020 ; Ren et al 2020 ; Yi et al 2016 ). We believe that the nature-like technology of thermal treatment that is centered around the process similar to the evaporation in a semiarid and arid climate is the golden mean, fast-operating and environmentally sound.…”

An effective thermal treatment of toluene-contaminated soil by uniform heating from microwave coupled infrared radiation (MCIR)

“…In recent years, thermal treatment method is now applied not only in the lab-scale experiments but also in the engineering practice owing to its high efficiency, convenient operation, and recyclable oil compounds (Cao et al 2018). For conventional thermal treatment, the heating method from the outside to the inside will inevitably cause a waste of energy, and it may be expensive due to the energy costs (Falciglia and Vagliasindi 2014;Li et al 2009). Therefore, it is necessary to find a new heating technology to improve the thermal treatment.…”