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Optimization of peroxidase-catalyzed oxidative coupling process for phenol removal from wastewater using response surface methodology

Ghasempur, S ; Sharif University of Technology | 2007

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  1. Type of Document: Article
  2. DOI: 10.1021/es070626q
  3. Publisher: 2007
  4. Abstract:
  5. Hydroxylated aromatic compounds (HACs) are considered to be primary pollutants in a wide variety of industrial wastewaters. Horseradish peroxidase (HRP) is suitable for the removal of these toxic substances. However, development of a mathematical model and optimization of the HRP-based treatment considering the economical issues by novel methods is a necessity. In the present study, optimization of phenol removal from wastewater by horseradish peroxidase (HRP) was carried out using response surface methodology (RSM) and central composite design (CCD). As the initial experimental design, 2 4-1 half-fraction factorial design (H-FFD) is accomplished in triplicate at two levels to select the most significant factors and interactions in the phenol removal procedure. Temperature (°C), pH, concentration of enzyme (unit mL-1), and H2O2 (mM) were determined as the most effective independent variables. Finally, a four factor-five coded level CCD, 30 runs, was performed in order to fit a second-order polynomial function to the results and calculate the economically optimum conditions of the reaction. The goodness of the model was checked by different criteria including the coefficient of determination (R2 = 0.93), the corresponding analysis of variance ((Pmodel > F) < 0.0001) and parity plot (r = 0.96). These analyses indicated that the fitted model is appropriate for this enzymatic system. With the assumption that the minimum enzyme concentration was 0.26 unit mL-1, the analysis of the response surface contour and surface plots defined the optimum conditions as follows: pH = 7.12, hydrogen peroxide concentration 1.72 mM, and 10°C. This work improves phenol removal operation economically by applying minimum enzyme concentration and highest removal in comparison with previous studies. © 2007 American Chemical Society
  6. Keywords:
  7. Central composite design ; Hydroxylated aromatic compounds ; Surface methodology ; Enzymes ; Mathematical models ; Optimization ; PH effects ; Phenols ; Toxicity ; Wastewater treatment ; Horseradish peroxidase ; Hydrogen peroxide ; Phenol ; Peroxides ; Concentration (composition) ; Coupling ; Enzyme activity ; Experimental design ; Oxidation ; Pollutant removal ; Wastewater ; Concentration response ; Enzyme assay ; Precipitation ; Response surface method ; Temperature sensitivity ; Waste water management ; Catalysis ; Oxidation-Reduction ; Peroxidases ; Water Pollutants, Chemical ; Armoracia rusticana
  8. Source: Environmental Science and Technology ; Volume 41, Issue 20 , 2007 , Pages 7073-7079 ; 0013936X (ISSN)
  9. URL: https://pubs.acs.org/doi/abs/10.1021/es070626q