title: Optimization for decolorization of azo dye acid green 20 by ultrasound and H2O2 using response surface methodology.
abstract: Response surface methodology (RSM) based on Box-Behnken design was successfully applied to the optimization of the operating conditions in decolorization of acid green 20 (AG 20) by ultrasonic irradiation in the presence of H(2)O(2). The effects of three operating variables, ultrasonic power density, initial pH value of dye solution and H(2)O(2) concentration on the decolorization efficiency of AG 20 were evaluated. A quadratic model for AG 20 decolorization was proposed. Analysis of variance (ANOVA) indicated that the proposed quadratic model could be used to navigate the design space. The proposed model was approximately in accordance with the experimental case with correlation coefficients R(2) and R(adj)(2) of 0.9995 and 0.9984, respectively. The optimum operating conditions for AG 20 decolorization were found to be 1.08 W/mL of ultrasonic power density, 4.85 of initial pH and 1.94 mM of H(2)O(2) concentration, respectively. The predicted decolorization rate under the optimum conditions determined by RSM was 96.8%. Confirmatory tests were carried out under the optimum conditions and the decolorization rate of 96.3% was observed, which closely agreed with the predicted value. The results confirmed that RSM based on Box-Behnken design was an accurate and reliable method to optimize the operating conditions of AG 20 decolorization.
authors.affiliation: Key laboratory of the Three Gorges Reservoir Region's Eco-Environment, State Ministry of Education, Chongqing University, Chongqing 400045, China.
authors.forename: Zhanmei
authors.initials: Z
authors.lastname: Zhang
authors.forename: Huaili
authors.initials: H
authors.lastname: Zheng
mesh_terms: D001391:Azo Compounds / Q000737:chemistry* / Q000528:radiation effects; D004396:Coloring Agents / Q000737:chemistry* / Q000528:radiation effects; D052918:Environmental Restoration and Remediation / Q000379:methods; D005505:Food Coloring Agents; D006861:Hydrogen Peroxide / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008086:Lissamine Green Dyes / Q000737:chemistry* / Q000528:radiation effects; D014465:Ultrasonics
chemical_list: D001391:Azo Compounds; D004396:Coloring Agents; D005505:Food Coloring Agents; D008086:Lissamine Green Dyes; D006861:Hydrogen Peroxide