Basic dye decomposition kinetics in a photocatalytic slurry reactor

• Published in: Journal of hazardous materials Vol. 137; no. 1; pp. 336 - 343
• Main Authors: Wu, Chun-Hsing, Chang, Hung-Wei, Chern, Jia-Ming
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.09.2006; Elsevier
• Subjects: Applied sciences; Biological and physicochemical phenomena; Catalysis; Catalytic reactions; Chemical engineering; Chemistry; Coloring Agents - chemistry; Dye decomposition; Equipment Design; Exact sciences and technology; General and physical chemistry; General purification processes; Hydrogen-Ion Concentration; Industrial Waste; Kinetic model; Kinetics; Models, Chemical; Natural water pollution; Photocatalysis; Photochemistry; Pollution; Reactors; Slurry reactor; Temperature; Textile Industry - methods; Textiles; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Time Factors; Titanium - chemistry; Waste Disposal, Fluid; Wastewaters; Water Pollutants, Chemical; Water Purification - instrumentation; Water Purification - methods; Water treatment and pollution; Slurry reactor; Kinetic model; Kinetics; Photocatalysis; Dye decomposition; Agitation; Energy cost; Pollutant behavior; Particle suspension; Basic dye; Modeling; Waste water; Pollutant; Ultraviolet radiation; pH; Water pollution; Reactor; Titanium oxide; Catalyst; Textile industry; Photochemical degradation
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2006.02.002

Wastewater effluent from textile plants using various dyes is one of the major water pollutants to the environment. Traditional chemical, physical and biological processes for treating textile dye wastewaters have disadvantages such as high cost, energy waste and generating secondary pollution during the treatment process. The photocatalytic process using TiO2 semiconductor particles under UV light illumination has been shown to be potentially advantageous and applicable in the treatment of wastewater pollutants. In this study, the dye decomposition kinetics by nano-size TiO2 suspension at natural solution pH was experimentally studied by varying the agitation speed (50–200rpm), TiO2 suspension concentration (0.25–1.71g/L), initial dye concentration (10–50ppm), temperature (10–50°C), and UV power intensity (0–96W). The experimental results show the agitation speed, varying from 50 to 200rpm, has a slight influence on the dye decomposition rate and the pH history; the dye decomposition rate increases with the TiO2 suspension concentration up to 0.98g/L, then decrease with increasing TiO2 suspension concentration; the initial dye decomposition rate increases with the initial dye concentration up to a certain value depending upon the temperature, then decreases with increasing initial dye concentration; the dye decomposition rate increases with the UV power intensity up to 64W to reach a plateau. Kinetic models have been developed to fit the experimental kinetic data well.