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

Authors: Reena Amatya Shrestha; Mika Sillanpää; Jarina Joshi; Ackmez Mudhoo

Addresses: Department of Civil and Environmental Engineering, Lehigh University, Bethlehem, PA, USA. ' Department of Environmental Sciences, University of Eastern Finland, Patteristonkatu 1, FI-50100 Mikkeli, Finland; Faculty of Technology, Lappeenranta University of Technology, Patteristonkatu 1, FI-50100 Mikkeli, Finland. ' Department of Biotechnology, Tribhuwan University, Kirtipur, Kathmandu, Nepal. ' Department of Chemical and Environmental Engineering, University of Mauritius, Réduit, Mauritius

Abstract: 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.

Keywords: azo dyes; catalysts; photodegradation; adsorption efficiency; photocatalytic degradation; supra black-T dye; charcoal; sunlight; industrial effluent; water pollution; carpet dyeing; wastewater treatment; ZnO; zinc oxide; TiO2; titanium dioxide; titania.

DOI: 10.1504/IJETM.2012.049223

International Journal of Environmental Technology and Management, 2012 Vol.15 No.3/4/5/6, pp.208 - 219

Published online: 17 Dec 2014 *

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