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Optimization of operating parameters for efficient photocatalytic inactivation of Escherichia coli based on a statistical design of experiments

Feilizadeh, M ; Sharif University of Technology | 2015

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  1. Type of Document: Article
  2. DOI: 10.2166/wst.2015.013
  3. Publisher: IWA Publishing , 2015
  4. Abstract:
  5. In this work, the individual and interaction effects of three key operating parameters of the photocatalytic disinfection process were evaluated and optimized using response surface methodology (RSM) for the first time. The chosen operating parameters were: reaction temperature, initial pH of the reaction mixture and TiO2 P-25 photocatalyst loading. Escherichia coli concentration, after 90 minutes irradiation of UV-A light, was selected as the response. Twenty sets of photocatalytic disinfection experiments were conducted by adjusting operating parameters at five levels using the central composite design. Based on the experimental data, a semi-empirical expression was established and applied to predict the response. Analysis of variance revealed a strong correlation between predicted and experimental values of the response. The optimum values of the reaction temperature, initial pH of the reaction mixture and photocatalyst loading were found to be 40.3°C, 5.9 g/L, and 1.0 g/L, respectively. Under the optimized conditions, E. coli concentration was observed to reduce from 107 to about 11 CFU/mL during the photocatalytic process. Moreover, all these results showed the great significance of the RSM in developing high performance processes for photocatalytic water disinfection
  6. Keywords:
  7. Response surface methodology ; Water disinfection ; Design of experiments ; Escherichia coli ; Mixtures ; Surface properties ; Central composite designs ; Operating parameters ; Photocatalytic disinfections ; Photocatalytic inactivations ; Photocatalytic process ; Statistical design of experiments ; Water disinfections ; Loading ; Titanium dioxide ; Catalysis ; Concentration (composition) ; Correlation ; Microbial activity ; Optimization ; Parameterization ; Photochemistry ; Reaction kinetics ; Bacterial strain ; Catalyst ; Colony forming unit ; Controlled study ; Nonhuman ; Particle size ; PH ; Process optimization ; Response surface method ; Temperature ; Water treatment ; Chemistry ; Drug effects ; Procedures ; Ultraviolet radiation ; Disinfection ; Hydrogen-Ion Concentration ; Photolysis ; Ultraviolet Rays
  8. Source: Water Science and Technology ; Volume 71, Issue 6 , 2015 , Pages 823-831 ; 02731223 (ISSN)
  9. URL: http://wst.iwaponline.com/content/71/6/823