Non-Thermal Atmospheric Pressure Plasma

Abstract

Plasma-chemical and plasma-processing systems are traditionally divided into two major categories: thermal and non-thermal ones. Non-thermal plasma offers high selectivity and energy efficiency of plasma-chemical reactions; it is able to operate effectively at low temperatures, in contact with fragile and delicate materials and does not require any quenching. This chapter focuses on the non-thermal atmospheric pressure plasma, highlighting its different phenomenons and practical applications. Non-thermal plasma may be produced by a variety of electrical discharges or electron beams. The basic feature of these various technologies is that they produce plasma in which the majority of the electrical energy primarily goes into the production of energetic electrons–instead of heating the entire gas stream. Some of the well-established phenomena such as the Townsend mechanism of electric breakdown of gases and in large gaps, Streamer breakdown mechanism, Leader breakdown mechanism, Corona discharge, pulsed Corona discharge, dielectric-barrier discharge, and spark discharges are described. The also chapter discusses technical issues involved In the development of a point-of-use water treatment system capable of inactivating waterborne microorganisms commonly found in drinking water through the implementation of plasma technology. There are many different types of electrode configurations that can be used to generate the plasma discharge in water, including a point-to-plane configuration and a coaxial configuration. Furthermore, a plasma-based water treatment system has many advantages compared to chemical or mechanical water treatment methods, such as very minimal maintenance, low operating power, and minimal pressure loss through the device. Therefore, a plasma based water treatment is advantageous in the implementation of a point-of-use water treatment system as well as in a large industrial water treatment.