A review on microwave assisted thermal remediation of hydrocarbons contaminated soil: Influential factors, mechanism, and prospective

This review provides an overview of current research on thermal methods for remediating soil contaminated with petroleum hydrocarbons, with a specific focus on microwave-assisted heating treatment. Initially, it broadly surveys and analyses existing studies on various thermal remediation techniques, in particular thermal desorption, pyrolysis, and incineration. The challenges of high temperatures, prolonged treatment durations, and substantial energy consumption underlying conventional heating methods were therefore summarised. Microwave heating approach was paid paramount attention in current review due to its distinct characteristics and widespread application in many fields, e.g. water treatment, solid waste management, and soil remediation. It offers distinct advantages over traditional thermal treatment methods, especially lower treatment temperatures, higher rates of pollutant recovery, and a very minimal disruption to soil biology. This paper then delves into the application and mechanisms of petroleum removal through microwave-assisted thermal remediation, and influential factors including soil and pollutant properties, the use of microwave-absorbing materials, and the effects of microwave radiation parameters were reviewed consequently. It can be concluded that microwave susceptors, irradiation power, and exposure duration, play crucial roles in optimising pollutant removal efficiency. While the technology offers significant benefits, including reduced energy consumption, a lower carbon footprint, and shorter remediation times, it is predominantly limited to ex situ applications due to constraints related to microwave penetration depth. Future research directions are proposed to enhance the effectiveness and practicality of microwave-assisted remediation in industrial contexts, emphasising the importance of scaling up laboratory findings to real-world scenarios.