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Photocatalytic decomposition of direct red 16 and kinetics analysis in a conic body packed bed reactor with nanostructure titania coated Raschig rings

Saien, J ; Sharif University of Technology | 2009

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  1. Type of Document: Article
  2. DOI: 10.1016/j.cej.2009.03.011
  3. Publisher: 2009
  4. Abstract:
  5. A conic body packed bed reactor, internally irradiated with a UV-C lamp and equipped with circulating upflow stream was employed to investigate the decomposition of a widely used azo dye, direct red 16, in water. The synthesized nanostructure TiO 2 photocatalyst particles were immobilized on the surface of transparent Raschig ring packings. Solutions with initial concentration of 30 mg L -1 of dye, within the range of typical concentration in textile waste waters, were treated under the mild operating conditions of natural pH of 6.75 and temperature of 25 °C. Investigations on the active species showed that hydroxyl radicals play the major role in the process, providing a perfect degradation in 90 min of irradiation and hence 93% in about 60 min; and also about 71% desired decomposition of aromatic groups in 120 min. For kinetic investigations, the rate of degradation of the dye was expressed as the sum of the rates of individual photolysis and photocatalysis process branches in power law model. Meanwhile, the Langmuir-Hinshelwood kinetic model describes the variations in pure photocatalytic branch in consistent with a first order power law model. © 2009 Elsevier B.V. All rights reserved
  6. Keywords:
  7. Kinetics ; Nanostructure TiO 2 ; Packed bed ; Active species ; Aromatic group ; Direct red 16 ; First order ; Hydroxyl radicals ; Initial concentration ; Kinetic investigations ; Kinetics analysis ; Langmuir-Hinshelwood kinetics ; Mild operating conditions ; Packed bed reactor ; Photo-catalytic ; Photocatalysis process ; Photocatalytic decomposition ; Photocatalytic degradation ; Power law model ; Raschig rings ; Textile wastewater ; TiO ; Titania ; Azo dyes ; Degradation ; Nanostructures ; Packed beds ; Photocatalysis ; Photolysis ; Sewage ; Textile finishing ; Titanium dioxide ; Titanium oxides ; Wastewater ; Wastewater treatment ; Photodegradation
  8. Source: Chemical Engineering Journal ; Volume 151, Issue 1-3 , 2009 , Pages 295-301 ; 13858947 (ISSN)
  9. URL: https://www.sciencedirect.com/science/article/abs/pii/S1385894709001752