ABSTRACT
OH radicals formed in water radiolysis may be effectively used for the oxidative decomposition of trichloroethylene and perchloroethylene contained as micropollutants in groundwater. Addition of ozone to the water before irradiation causes the reducing species of the water radiolysis to be converted into OH radicals. Moreover, this eliminates the dose rate effect observed with irradiation alone. By the ozone-electron beam treatment greater than 95% of the organic chlorine content are mineralized, only negligible amounts of organic chlorine containing by-products are formed. AMES test has shown no mutagenic activity at all.
Subject(s)
Ozone/administration & dosage , Tetrachloroethylene , Trichloroethylene , Water Pollution, Chemical/prevention & control , Water/radiation effects , Electrons , Hydroxides , Hydroxyl RadicalABSTRACT
Solutions of 10 ppm trichloroethylene in air-saturated drinking waters are decomposed by gamma radiation with initial G-values, G0, around 3-5 molecules per 100 eV. At lower concentrations, the G0-values decrease with decreasing trichloroethylene concentration and with increasing amounts of inorganic (especially HCO3- and NO3-) and organic solutes. From the results, a semi-empirical formula is derived which allows an estimation of G0-values for the trichloroethylene decomposition in drinking waters of given composition.
Subject(s)
Trichloroethylene/radiation effects , Water Pollution, Chemical/prevention & control , Water SupplyABSTRACT
The gamma-radiation degradation of trace amounts (70-440 ppb) of trichloroethylene and tetrachloroethylene in drinking water has been investigated. The doses necessary to reduce the pollutant concentration to 1 ppb are in the order of 1 kGy.
