Environmental Perspectives of Microwave Applications as Remedial Alternatives: Review

Microwave energy has been widely used in several domestic, industrial, and medical applications such as food sterilization, organic/inorganic syntheses, polymerization, dehydration, analyses and extraction, and biological destruction. This paper summarizes the potential applications of microwave energy as remedial alternatives for various types of wastes and diverse contamination of soils, sludge, or wastewaters. The major subjects covered in the paper are focused on sludge processing, medical waste treatment, contaminated soil remediation, wastewater remediation, activated carbon regeneration, and integrated remedial methodology. The extent of microwave treatment and microwave-assisted application promoting a specific technology has been highlighted relative to the conventional methods. Also, a few novel microwave involved processes, and the integrated experimental design of remedial schemes were presented. The application of microwave energy was proven to be superior to the use of conventional heating on accelerating reaction rates, improving yields, and selectively activating or suppressing reaction pathways. Besides the thermal effect, the nonthermal effect caused by microwave irradiation and its influence on the specific remediation cases have also been discussed. When applying the integrated remedial methodology, the effects of microwave irradiation improving the photocatalytic capacity of TiO2 have been detailed. Conclusively, microwave technology is a potentially viable and powerful alternative to the decontamination of soil, sludge, wastewater, as well as the treatment of certain types of waste. DOI: 10.1061/ ASCE 1090-025X 2008 12:2 102 CE Database subject headings: Microwaves; Remedial action; Thermal energy; Waste treatment; Environmental issues.