REMOVAL OF VOLATILE ORGANIC-COMPOUNDS IN WATER USING LOW-ENERGY-ELECTRON BEAM

This paper presents the experimental results concerning removal of org anic contaminants in water using low energy electron beam radiation. A laboratory scale apparatus for electron beam irradiation of water is described. The absorbed dose of radiation was controlled by water circ ulation time (1 to 10 min), accelerating voltage (100 to 170 kV), and electron beam current (0.5 to 1.2 mA) for a constant flow rate of 2 kg /min. The volume of the treated water was 1 dm(3). The electron beam w as generated in vacuum (p < 10(-5) Pa), and electrons were injected in to the water through the electron transparent window made of titanium foil with a thickness of 25 mu m. TCE (trichloroethylene) and chlorofo rm dissolved in deionized water were used in the experiment. The depen dency of the relative concentration c = C/C-0; where C is the weight c ontent of compound after electron irradiation and C-0 the initial cont aminant concentration, on radiation energy density and the absorbed do se are presented. Although the initial contents of the compounds were higher than those occurring in real water sources, it has been found t hat it is possible to decompose both of the chemicals with high effici ency (total decomposition of TCE, and up to 90% reduction of chlorofor m) using a relatively low accelerating voltage (<200 kV). The results have indicated that the removal of TCE and chloroform mainly depended on the absorbed dose of electron radiation.