PHOTOCATALYTIC DEGRADATION OF ORGANOCHLORINE COMPOUNDS IN SUSPENDED TIO2

Twelve organochlorine solvents which are di-, tri- and tetrachloro derivatives of methane, ethane and ethylene, were photocatalytically degraded on TiO2, platinum (Pt)-loaded TiO2 and TiO2 with added H2O2. It was found that for derivatives of the three compounds the degradation rates were in the order Cl2 > Cl3 > Cl4, and for those containing the same number of Cl substituents the order was ethylene > ethane. During the degradation of each organochlorine solvent, Cl- was liberated simultaneously. On Pt-loaded TiO2, Cl- was transformed into ClO3- photocatalytically. Stoichiometry for the photocatalytic degradation of dichloroethylene was C2H2Cl2 + 2O2 → 2Cl- + 2CO2 + 2H+. © 1990.