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Studies on the Mineralization and Separation Efficiencies of a Magnetic Photocatalyst

“…This indicated that while the methylene blue was degraded to the point were the color was lost, it was not completely oxidized to carbon dioxide. This had been previously reported by other studies carried out on the degradation of methylene blue [3,14]. Such studies have indicated the formation of reaction intermediates and pointed to the difficulty of completely oxidizing organic dyes.…”

“…3. The results show that in all cases, the catalyst addition resulted in an immediate drop in the methylene blue concentration in solution.…”

“…This is seen to be due to either agglomeration of the particles following the magnetic separation and the drying step, or a loss in active sites due to the deposition of the reaction intermediates onto the surface of the catalyst. The systematic degradation in the performance of recycled photocatalysts following the degradation of textile wastewater has been previously reported [3,4]. Both these studies involved the use of filtration to recover the photocatalyst particles.…”

“…Both these studies involved the use of filtration to recover the photocatalyst particles. Sopajaree et al [3] suggested the decrease in photoactivity to be due to agglomeration of the TiO 2 particles with repeated use in the integrated photoreactor filtration assembly. Freudenhammer et al [15] suggested that during the photodegradation of textile wastewater, the pollutant or the products of the pollutant oxidation (such as chlorine anions) compete with each other for active surface sites of the irradiated photocatalyst decreasing its activity.…”

“…Ultrafiltration and microfiltration of the catalyst particles have also been investigated [3,4]. Separation techniques, such as centrifugation and filtration, which are dependent on particle size suffer from poor selectivity and substantial loss of valuable components when separating and recovering of colloidal particles [5].…”