ELECTRON-BEAM ATMOSPHERIC-PRESSURE COLD-PLASMA DECOMPOSITION OF CARBON-TETRACHLORIDE AND TRICHLOROETHYLENE

The cold plasma decomposition of carbon tetrachloride (CCl4) and trich loroethylene (C2HCl3) at dilute concentrations in dry and wet air of a tmospheric pressure was investigated. The cold plasma was generated in a tunable plasma reactor, where the electron concentration is control led by an electron beam and the average electron energy is controlled by a superimposed sub-breakdown electric field. The energy expense for decomposition, i.e., the electron beam energy per molecule decomposed , as well as the intermediate and final decomposition products were de termined. Moreover, likely reaction mechanisms for the decomposition o f CCl4 and C2HCl3 are presented. These mechanisms are based on bimolec ular dissociative electron attachment for both CCl4 and C2HCl3 and add itionally a chlorine chain reaction for C2HCl3. The present work provi des a reference for the development of an advanced oxidation process o n the basis of a tunable plasma reactor. Such a process would be espec ially suitable for the treatment of air contaminated with chemical com pounds that dissociatively attach electrons.