Experimental Study and Kinetic Modeling of Chloroform Decomposition in Aqueous Solutions under the Action of γ-Radiation

Abstract

The radiolysis of aqueous chloroform solutions (10^–3–10^–2 M) in the presence of dissolved oxygen is studied to establish a chain mode for the decomposition of chloroform. CO₂, H₂, H₂O₂ and chlorinated hydrocarbons-dichloromethane and dichloroethane are identified as products of the radiolysis of aqueous chloroform solutions. Changes in the pH and COD from the absorbed dose for the radiolysis of an aqueous chloroform solution with a concentration of 4.2 × 10⁻² M are studied. It is found that as the dose is increased, the pH index and COD fall, indicating the decomposition of organic compounds and the formation of acids. It is shown that the radiation-chemical yields of chloroform decomposition depend on its initial concentration. At ≥4.2 × 10⁻² M, they lie in the range of 52–245 molec./100 eV. A formal kinetic scheme of the processes that occur during the γ-radiolysis of aqueous chloroform solutions is compiled using the obtained data and allowing for the available literature values of the rate constants of elementary reactions.