Document Type: Original Research Paper
Department of Environmental Science, Graduate School of the Environment, Science and Research Branch, Islamic Azad University, Tehran, Iran
Department of Pharmacology, Faculty of medicine, Shahid Beheshti University of Medical Sciences (SBMU), Tehran, Iran
Department of Environment, Institute of Iranian Mineral Processing Research, Kavosh research town, 9 km Qazvin / Karaj Freeway, Iran
Environmental pollution by 2,4-dicholorphenol (2,4-DCP), commonly found in industrial
wastewater has been a concern for humans over the past 50 years. Garden Radish Peroxidase (GRP) can eliminate this poisonous pollutant. The aim of this study was to apply an experimental Response Surface Methodology (RSM) and Central Composite Design (CCD) to optimize GRP-based treatment in order to maximize the removal of 2,4-DCP from wastewater. The effects of four factors; pH, enzyme activity (U/mL), hydrogen peroxide (H2O2) concentration (mM), and substrate concentration (mg/L) and their interactions were investigated for 2,4-DCP removal using a second-order polynomial model. The suitability of the polynomial model was described using coefficient of determination (R2 =90.7%) and the results were created by analysis of variance (ANOVA). A 3D response surface was made from the mathematical models and then applied to
determine the optimal condition. These analyses exhibited that using a quadratic model was fitting for this treatment. Furthermore, desirability function was employed for the specific values of controlled factors for optimization and maximum desirability. Based on the desirability function results, the response predicted a 99.83% removal rate of 2,4-DCP from wastewater with 0.959 desirability. Under these conditions, the experimental removal percentage value would be 99.2%.