Recent advances of cold plasma technology for water and soil remediation: A critical review

The intense presence of toxic substances in drinking water and landfills caused by the growing industrialization and the extensive use of chemicals, established wastewater and contaminated soil treatment to be an urgent and challenging concern of societies. The removal of contaminants from soil and wastewater in modern treatment plants is often incomplete, particularly with reference to complex organic compounds. Considering its environmental compatibility, high contaminants removal and high energy efficiency of the process, cold plasma is considered a promising remediation method. To that end, wanting to achieve optimum results, numerous efforts have been recorded describing the development of different plasma remediation systems by examining meticulously and with different points of view various reactors’ configurations, plasma discharge types generated inside or outside contaminated medium, in the presence or the absence of catalysts, etc. The design and consideration though of all critical parameters towards the establishment of an ideal setup is not profound. The main goal of this review is to critically assess, compare and correlate the latest developments focused on achieving optimum remediation results in terms of energy and pollutant degradation efficiency, analyze the most critical factors and limitations and most importantly to explore the perspectives for developing effective upscaled systems; suggestions for future trends are put forward. Among the most important challenges, the maximization in the production of available reactive species, the large contact area between plasma and pollutants and to ensure the feasibility of the method in real life conditions are crucial. This review aims to provide researchers with a deeper understanding of the several aspects of cold plasma as remediation technology by looking forward on the key-role steps required for its industrial implementation.