Photochemical methods for abating environmental pollution

This thesis elaborates on abating environmental pollutants using photocatalytic methods. The methods include heterogeneous and homogeneous photocatalysis using titanium dioxide and hydrogen peroxide, respectively. Formaldehyde was used as a model pollutant. For the heterogeneous method, the kinetic aspects of the process were described with substrate initial concentration and light intensity as variables. The chemical oxygen demand was used to obtain the residual carbon content. Decomposition profiles of formaldehyde with and without titanium dioxide were examined with CuSO{dollar}sb4{dollar} (aq) as a light filter. The influence of purge gas on the photocatalytic reaction was presented. The hydrogen peroxide for homogeneous photocatalysis was generated in-situ by electrochemical reduction of oxygen. The effects of applied current on hydrogen peroxide generation and percent conversion of formaldehyde were studied. The UV light and nitrogen gas effects were also examined. Comparisons of process effectiveness were made between commercial hydrogen peroxide and the in situ UV/H{dollar}rmsb2Osb2{dollar} process variant.