Chemical Engineering and Processing, Vol.130, 53-60, 2018
Pilot scale applications of microwave heating for soil remediation
Thermal remediation technologies are very efficient for the removal of lipophilic organic contaminants from solid waste or soil. Compared to conventional heating method that is energy consuming due to the low thermal conductivity of contaminated material, microwaves bring several benefits for thermal solids treatment. There are three different approaches for the application of microwave heating for remediation - 1) contaminated material heating in a kiln, 2) the in-situ heating of contaminated surfaces and 3) the in-situ heating of subsurface soil environment. We developed and tested the pilot units for these applications including efficient off-gas treatment system. The pilot remediation tests were performed using 6 kW 2.45 GHz industrial microwave generators for the treatment of materials from several contaminated sites. During the tests, we measured detailed spatial temperature and contaminants mass distribution in the tested material. The achieved results confirmed promising data from laboratory tests and the high efficiencies of different contaminants removal were achieved at mild temperatures and with low energy consumption. Moreover, we gained important empirical knowledge about these innovative remediation technologies that has allowed to determine practical limitations for further scale-up and field applications or to validate future numerical models.