Optimization of Ultrasonication Process for the Degradation of Linear Alkyl Benzene Sulfonic Acid by Response Surface Methodology

Abstract

The optimization of ultrasonication process applied to linear alkyl benzene sulfonic acid (LABSA) degradation is investigated with response surface methodology in this study. Methylene blue active substance assay is used as a mean to monitor the degradation of LABSA. The effects of independent process variables (initial LABSA concentration, pH, and reaction time) on main material degradation are investigated. Among the independent variables, the greatest effect on LABSA degradation is observed for reaction time. Besides this, the effects of both reaction time and initial LABSA concentration are quite similar. The initial pH value of the solution has a lower effect on degradation performance when compared to other parameters. The predicted maximum detergent degradation was 75% at the optimal conditions of pH 7.8, initial LABSA concentration of 20 mg L−1, and reaction time of 70 min. Specific cost of LABSA degradation by ultrasonic treatment varies from 0.579 to 4.657 Euro g−1 removal LABSA. According to the results of sonication treatment applied to real wastewater, approximately 40% of the LABSA degradation is achieved at three pH values (5.27, 7.50, and 9.59). Because the original pH of the real wastewater is 9.59, it is more feasible to run experiments at this pH value.