%0 Journal Article %T Application of Response Surface Methodology to Enhance Phenol Removal from Refinery Wastewater by Microwave Process %A Sherif A. Younis %A Waleed I. El-Azab %A Nour Sh. El-Gendy %A Shuokr Qarani Aziz %A Yasser M. Moustafa %A Hamidi Abdul Aziz %A Salem S. Abu Amr %J International Journal of Microwave Science and Technology %D 2014 %I Hindawi Publishing Corporation %R 10.1155/2014/639457 %X Phenol contaminated petroleum refinery wastewater presents a great threat on water resources safety. This study investigates the effect of microwave irradiation on removal of different concentrations of phenol in an attempt for petroleum refinery wastewater treatment. The obtained results show that the MW output power and irradiation time have a significant positive effect on the removal efficiency of phenol. The kinetic reaction is significantly affected by initial MW output power and initial phenol concentrations. Response surface methodology (RSM) was employed to optimize and study the interaction effects of process parameters: MW output power, irradiation time, salinity, pH, and H2O2 concentration using central composite design (CCD). From the CCD design matrix, a quadratic model was considered as an ultimate model ( 2£¿=£¿0.75) and its adequacy was justified through analysis of variance (ANOVA). The overall reaction rates were significantly enhanced in the combined MW/H2O2 system as proved by RSM. The optimum values for the design parameters of the MW/H2O2 process were evaluated giving predicted phenol removal percentage of 72.90% through RSM by differential approximation and were confirmed by experimental phenol removal of 75.70% in a batch experiment at optimum conditions of 439£¿W MW power, irradiation time of 24.22£¿min, salinity of 574£¿mg/L, pH 5.10, and initial H2O2 concentration of 10% (v/v). 1. Introduction The main recalcitrant organic material found in petroleum refinery wastewater (PRWW) effluent is phenol due to its high water solubility behavior (86£¿g/L) and resistance to conventional physicochemical treatment methods, for example, oil separation, coagulation, and flocculation [1, 2]. The phenol concentration in the PRWW effluent is generally in the range of 20¨C200£¿mg/L [3, 4], while US Environmental Protection Agency, WHO study in 1998, and Environmental Egyptian Law Number 4, 1994 for wastewater considered phenols as priority pollutants and lowered their content in the wastewater stream to less than 1£¿mg/L as maximum concentration limit [5]. Due to the phenol propensity to initiate carcinogenic and mutagenic effects on terrestrial as well as aquatic biota and human [6], PRWW effluent needs additional treatment before its final disposal to reduce the phenol concentrations in the wastewaters to accomplish the requirements for discharge in the receiving body and comply with relevant Egyptian and international standards for water recycling and reuse. Over the past few decades, advanced oxidation processes (AOP) have received increasing %U http://www.hindawi.com/journals/ijmst/2014/639457/