The present work reports treatment of synthetic phenolic wastewater by electrocoagulation process. Aluminum flat heets were utilized as electrodes. Central composite design combined with response surface methodology has been applied for optimizing the process parameters. The interaction effects of phenol concentration, electrode distance, pH, voltage, and electrolysis time (ET) were analyzed and correlated to assess the efficiency of phenol removal as process response. The ANOVA outcomes declared that the initial phenol concentration (relevant coefficient = −3.44) and ET (relevant coefficient = 1.42), respectively, are the most and the least effective parameters on the efficiency of phenol removal. Furthermore, optimal factors were obtained as follows: influent phenol concentration = 14.23 mg/L, electrode distance = 2.20 cm, pH = 6.37, voltage = 16.46 V, and electrolysis time = 44.66 min, in which the percentage of phenol removal at this condition was about 90.6%.
