| The global focus on waste minimization and water preservation and management has also led to the production of highly toxic waste, both in the water and gaseous states. It is imperative that these are treated and disposed of in a proper and effective manner. Oxidation techniques are effective for degradation of toxic wastes; however the majority of the existing oxidation technologies are not capable of complete mineralization of many toxic compounds. Advanced Oxidation Processes (AOP) are generally an exception. AOPs by defination a process that generate hydroxyl radicals (OH·) in quantities sufficient to oxidize the majority of organic and inorganic toxic compounds commonly found in domestic and industrial wastewater streams.; Photocatalysis using a titanium dioxide (TiO2) catalyst is one of such process, capable of degrading many toxic compounds into less harmful by-products. While it is very effective when applied as slurry, these slurry systems require the separation of the semiconductor catalyst prior to disposal, an event that can render this technology very expensive.; Researchers are exploring the immobilization of TiO2 semiconductor photocatalyst with the aim of reducing the need for catalyst separation in slurry systems. The research reported herein evaluates the effectiveness of the cathodic deposition method for the preparation of an immobilized catalyst film for treatment of cyanide and organic wasterwaters. Films prepared by this method were deposited on conducting substrates to take advantage of electric field enhancement (EFE). The effect of pH, oxygen and bias potential on phototcatalytic degradation of toxic compounds, were explored using this film.; The films developed were tested on the degradation of both organic and cyanide and found to be photocatalytically active in each case. Although bias potential and pH proved to have a synergetic effect on the degradation of the selected model compounds, no synergetic effect was observed between pH and gas. |
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