DECOMPOSITION OF GAS-PHASE CHLOROETHENES BY UV O-3 PROCESS/

The photolytic behaviors of gas-phase I,1-dichloroethylene (DCE), tric hloroethylene (TCE), and perchloroethylene (PCE) in air streams by ult raviolet irradiation and UV/O-3 process were studied. The addition of ozone slightly improved the removal of TCE by UV/O-3 process, and exce ssive ozone would reduce the treatment efficiency of TCE. The enhancem ent of UV light intensity would promote the decomposition of TCE more effectively than the supplement of ozone. The mineralization and dechl orination of chloroethylenes by UV photolysis can be apparently promot ed in presence with ozone and were affected by the number of chlorine atom substituted on the CC bond. The photolytic behaviors bf TCE and t he individual contribution to the decomposition of TCE by UV direct ph otolysis and by OH destruction in the UV/O-3/TCE system were well mode led by the proposed decomposition scheme. (C) 1998 Elsevier Science Lt d. All rights reserved.