Synthesis of activated carbon/magnetite nanocatalyst for sono-Fenton-like degradation process of 4-chlorophenol in an ultrasonic reactor and optimization using response surface method

Abstract

Effective removal of 4-chlorophenol, a toxic and persistent organic pollutant, from wastewater is of utmost importance for environmental preservation and human well-being. The aim of this study is to design a new reactor for the quasi-Fenton process to increase the degradation efficiency of 4-chlorophenol using ultrasonic waves. For this purpose, activated carbon/magnetite nanocatalyst was synthesized using active carbon obtained from used tires and Fe3O4 nanoparticles prepared by the chemical coprecipitation method. The characterization of the active carbon/magnetite nanocatalyst showed a specific surface area of 172.46 m2g−1, and the size of the nanocatalyst was 10 nm. In addition, FTIR, EDX and XRD analyses were also investigated to identify the nanocatalyst. Evaluation of mechanical and chemical resistance confirmed the stability of the nanocatalyst. The degradation process of 4-chlorophenol was optimized using the RSM method. The experimental findings indicated that the optimal operating conditions for maximizing 4-chlorophenol removal efficiency were found to be pH 3, temperature 42 °C, nanocatalyst dose 2 gL−1, hydrogen peroxide concentration 25.58 mM ultrasonic power 320 W, and reaction time of 78 min. The validity of these optimal conditions was further confirmed through real-world experiments, resulting in remarkable removal efficiencies of 97.32 % and 93.47 % for 4-chlorophenol concentrations of 250 and 500 mgL−1, respectively.