Optimization of F¯ Removal From Wastewater Utilizing Alternating Current Electrocoagulation Coupled With Sonication Using a Statistical Design Approach

Abstract

Combining electrochemical and advanced oxidation processes (AOPs) has greatly mitigated the limitations of electrocoagulation (EC) in water treatment. This study examined the effectiveness of sonolysis (US)-assisted alternating current (AC)–EC in reducing fluoride (F¯) from landfill leachate wastewater (LLW), with measurements of electrical energy consumption (EEC). The experimental results indicated that the US-assisted AC–EC (US+AC–EC) process achieved greater reduction in F¯ from wastewater. To treat LLW, the US+AC–EC process different operational parameters were optimized using response surface methodology (RSM) based on central composite design (CCD). The effects of five independent parameters, such as sonication power (A) and pulse duty cycle (B), F¯ concentration (C) and current density (D), and reaction time (E) on F¯ reduction (%) and EEC were studied. A quadratic model was used to predict the decrease of F¯ and EEC under various conditions. ANOVA, or analysis of variance, was used to assess the significance of independent variables and their interactions. The optimal conditions for achieving maximum reduction of F¯ and the least amount of EEC were determined using statistical and mathematical methods. The optimal conditions for achieving the maximum amount of F¯ (81%) removed with the minimum amount of EEC (8.64 kWh/m³) include the following: A—60 W, B—0.45, C—12 mg/L, D—0.6 A/dm², and E—22.50 min. The US+AC–EC process has proved to be an effective and efficient method for removing F¯ from LLW with the least amount of EEC and that CCD is a viable method for improving the process. In conclusion, the US+AC–EC process has the potential to efficiently remove contaminants from wastewater.