Optimization of Peroxidase-Catalyzed Oxidative Coupling Process for Phenol Removal from Wastewater Using Response Surface Methodology

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• 作者：Salehe Ghasempur ; Seyed-Fakhreddin Torabi ; Seyed-Omid Ranaei-Siadat ; Mehdi Jalali-Heravi ; Nasser Ghaemi ; Khosro Khajeh
• 刊名：Environmental Science & Technology
• 出版年：2007
• 出版时间：October 15, 2007
• 年：2007
• 卷：41
• 期：20
• 页码：7073 - 7079
• 全文大小：263K
• 年卷期：v.41,no.20(October 15, 2007)
• ISSN：1520-5851

文摘

Hydroxylated aromatic compounds (HACs) are considered tobe primary pollutants in a wide variety of industrialwastewaters. Horseradish peroxidase (HRP) is suitable forthe removal of these toxic substances. However, developmentof a mathematical model and optimization of the HRP-basedtreatment considering the economical issues by novel methodsis a necessity. In the present study, optimization of phenolremoval from wastewater by horseradish peroxidase (HRP) wascarried out using response surface methodology (RSM) andcentral composite design (CCD). As the initial experimental design,2^4-1 half-fraction factorial design (H-FFD) is accomplished intriplicate at two levels to select the most significant factors andinteractions 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 performedin order to fit a second-order polynomial function to theresults and calculate the economically optimum conditions ofthe reaction. The goodness of the model was checked bydifferent criteria including the coefficient of determination (R ²= 0.93), the corresponding analysis of variance ((P_model > F)< 0.0001) and parity plot (r = 0.96). These analyses indicatedthat the fitted model is appropriate for this enzymaticsystem. With the assumption that the minimum enzymeconcentration was 0.26 unit mL^-1, the analysis of the responsesurface contour and surface plots defined the optimumconditions as follows: pH = 7.12, hydrogen peroxideconcentration 1.72 mM, and 10 C. This work improves phenolremoval operation economically by applying minimumenzyme concentration and highest removal in comparisonwith previous studies.