Photocatalytic degradation of supra black-T dye on charcoal under sunlight

Azo dyes are used in many industries such as carpet manufacturing, textiles, paint, ink, plastics and cosmetics production processes. The coloured industrial effluent can pose serious problems in the aquatic environment. It is possible to get complete mineralisation of organic pollutants in water by photocatalysts. This study was carried out to examine the feasibility to remove supra black-T dye from carpet dyeing wastewater by photocatalytic degradation on Oak charcoal under sunlight. Adsorption efficiency of dye on charcoal at various pH values and photodegradation with ZnO and TiO₂ catalysts were studied. The removal efficiency of charcoal alone was 28 mg dye/g charcoal at pH 8 and 25°C in 60 min which was half that of activated charcoal. Photocatalytic degradation and adsorption with TiO₂ and ZnO under sunlight was faster and almost complete removal was observed in shorter times.