Photocatalytic degradation of model textile dyes in wastewater using ZnO as semiconductor catalyst

• Published in: Journal of hazardous materials Vol. 112; no. 3; pp. 269 - 278
• Main Authors: Chakrabarti, Sampa, Dutta, Binay K
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 30.08.2004; Elsevier
• Subjects: Applied sciences; Catalysis; Coloring Agents - chemistry; Dye-degradation; Eosin Y; Exact sciences and technology; General purification processes; Hydrogen-Ion Concentration; Kinetics; Methylene Blue; Osmolar Concentration; Photocatalysis; Photochemistry - methods; Pollution; Semiconductors; Textile Industry - methods; Wastewaters; Water Pollutants, Chemical - analysis; Water Pollution, Chemical - prevention & control; Water treatment and pollution; Zinc Oxide - chemistry; ZnO-photocatalyst; Methylene Blue; Eosin Y; Dye-degradation; Photocatalysis; ZnO-photocatalyst; Dyes; Pollutant behavior; Modeling; Waste water; Pollutant; Ultraviolet radiation; Batchwise; Loading; Chemical oxygen demand; Mineralization; Water quality; Visible radiation; pH; Reactor; Catalyst; Textile industry; Photochemical degradation
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2004.05.013

Semiconductor photocatalysis often leads to partial or complete mineralization of organic pollutants. Upon irradiation with UV/visible light, semiconductors catalyze redox reactions in presence of air/O 2 and water. Here, the potential of a common semiconductor, ZnO, has been explored as an effective catalyst for the photodegradation of two model dyes: Methylene Blue and Eosin Y. A 16 W lamp was the source of UV-radiation in a batch reactor. The effects of process parameters like, catalyst loading, initial dye concentration, airflow rate, UV-radiation intensity, and pH on the extent of photo degradation have been investigated. Substantial reduction of COD, besides removal of colour, was also achieved. A rate equation for the degradation based on Langmuir–Hinshelwood model has been proposed.