Use of Microwaves for Disinfection of Farmland: a Feasibility Study

Abstract

This work focuses on the heat transfer dynamics in agricultural soils when exposed to microwave (MW) fields, in order to disinfect them and to eliminate dangerous organisms without using pesticides. The work managed with the design of a horn antenna, with fixed feeding power, to be used to irradiate the superficial layer of soils for a fixed depth. The soil was approximated with a transmission line model, i.e. a lumped electrical model. By this model, after evaluating the relevant physical parameters such as the dielectric constant (as a function of the soil water content), it was possible to evaluate the power absorption and, finally, the increase in temperature and its profile as a function of the irradiation time. The latter information, strictly connected to the heat transfer process, demonstrated the feasibility of the methodology here proposed to achieve difficult conditions for microbial and pathogens life and so an effective disinfection of the treated farmland.