Decomposition of gas-phase chloroethenes by UV/O3 process

The photolytic behaviors of gas-phase 1,1-dichloroethylene (DCE), trichloroethylene (TCE), and perchloroethylene (PCE) in air streams by ultraviolet irradiation and UV/O3 process were studied. The addition of ozone slightly improved the removal of TCE by UV/O3 process, and excessive ozone would reduce the treatment efficiency of TCE. The enhancement of UV light intensity would promote the decomposition of TCE more effectively than the supplement of ozone. The mineralization and dechlorination of chloroethylenes by UV photolysis can be apparently promoted in presence with ozone and were affected by the number of chlorine atom substituted on the C=C bond. The photolytic behaviors of TCE and the individual contribution to the decomposition of TCE by UV direct photolysis and by OH• destruction in the UV/O3/TCE system were well modeled by the proposed decomposition scheme.