A comparative study of advanced oxidation-based hybrid technologies for industrial wastewater treatment: An engineering perspective

Abstract

In this paper, several advanced oxidation-based hybrid technologies were employed to efficiently remove organic pollutants from industrial wastewater. First, the efficiency of hybrid treatment systems composed of coagulation-flocculation, electrochemical oxidation (ECO), and ozone oxidation for removal of several landfill leachates were investigated and the effects of coagulation-flocculation with different chemicals, including polyaluminum chloride, anionic polymers, calcium-based compounds, and sodium carbonate were studied. Coagulation-flocculation/ECO/Ozone oxidation hybrid system achieved the best performance (90.65% removal rate) for fluoride removal, compared with ECO alone and coagulation-flocculation/ECO systems. With a 92.2% fluoride removal rate, Ca(OH)2 achieved the best performance among all calcium-based hybrid treatment technologies. Then, the role of Fenton oxidation/adsorption hybrid technologies in industrial wastewater treatment were also investigated and compared with adsorption and Fenton oxidation alone. Fenton oxidation-adsorption technology achieved a high TOC removal rate of 97%, which was 2.42 times higher than that obtained by activated carbon alone (41.4%) and 1.56 times higher than that achieved by the homogeneous FO process alone (63%). Finally, factors influencing the efficiency of pollutant degradation, including initial pH value, pollutant concentration, and current density were evaluated.