PHOTOCATALYTIC MINERALIZATION OF PERCHLOROETHYLENE USING TITANIUM-DIOXIDE

The photocatalytic mineralisation of perchloroethylene (PCE) is demons trated mainly in terms of CO2 formation to investigate the effects of various factors such as dissolved oxygen (DO), titanium dioxide semico nductor (TiO2) catalyst dosage, PCE concentration and pH on PCE photoc atalysis. PCE was rapidly adsorbed onto the TiO2 particles followed by its gradual degradation, and CO2 production started after a short lag time that corresponded to the adsorption phase. The rate of CO2 forma tion increased with increasing DO, TiO2 dosage and PCE concentration. There was no significant effect of initial pH on the CO2 production ra te over a wide pH range. The dependence of the CO2 formation on PCE co ncentration was found to obey the Langmuir-Hinshelwood model. No inter mediates were detected during PCE degradation and PCE degradation foll owed a first-order reaction.