Wyniki 1-1 spośród 1 dla zapytania: authorDesc:"Agnieszka MIRKOWSKA"

Decolorization of methylene blue in aqueous medium using dielectric barrier discharge plasma reactor DOI:10.15199/48.2017.08.48

Czytaj za darmo! »

Plasma can be defined as a neutral ionized (partially or fully) gas consisting of various particles, such as electrons, ions, atoms, and molecules. It is also called as the fourth state of matter and more than 99% of the matter in the Universe exists as plasma state. It is possible to distinguish two types of plasmas: non-thermal and thermal. This classification is based on the relative energetic levels of “light" (electrons) and “heavy" species (ions, molecules and atoms) of the plasma. Thermal plasma occurs when all particles are at thermal equilibrium, typically at high pressure (above 105 Pa) and large power density. In nonthermal plasmas there is no equilibrium between particles - temperatures (kinetic energy) of electrons and other particles are totally different. The electron temperature is much (about 3 orders) higher than the gas temperature, which is close to ambient temperature. This kind of plasma is also defined as non-equilibrium or cold plasma and can be obtained at lower pressures and for lower power. High energetic electrons play an essential role in the initiation of plasma chemistry reactions so plasma is chemically active media. The main non-thermal plasma (NTP) applications are waste gas and water treatment, surface treatment of polymeric materials, sterilization process and deactivation of microorganisms [1-3]. There are many types of NTP reactors: corona discharge, dielectric barrier discharge (DBD), surface discharge, ferroelectric pellet packed-bed reactor, plasma jet, and gliding arc, etc. Regarding the water treatment, the type of applied NTP reactor depends mostly on the medium, where discharges occur: in gas, liquid or gas-liquid phase. In consequence the phenomena leading to degradation of wastes differs depending on the medium, what result in various values of energy yield. The higher energy yields may be obtained when the reactive species are generated in gas and transported to l[...]

 Strona 1