Integrated Advanced Oxidation Processes for Chlorophenol Degradation: Parameter Influence, Efficacy Evaluation, and Toxicity Assessment with Eichhornia crassipes

Abstract

This study investigated the degradation of a mixture of chlorophenol solution using various Advanced Oxidation Processes (AOPs). At different optimized conditions obtained for trichlorophenol, dichlorophenol, and monochlorophenol individually, additional optimization was performed for treating mixed chlorophenols (Mi-CPs). In photocatalysis degradation, rapid and complete removal of Mi-CPs was reported at pH 6.0, TiO₂ dose of 0.25 g/L, and H₂O₂ concentration of 10.0 mM within 270 min. In the case of photo-Fenton’s process, the complete removal was observed in 12 min at pH 3.0, Fe(II) 0.5 mM, and H₂O₂ 10.0 mM. Different AOPs integrated methods were also employed towards efficient removal. Solar-derived processes exhibited enhanced degradation rates. Assessment of electrical energy per unit order indicated sonication or UV-driven processes as energy-intensive processes over solar processes. For instance, solar-Fenton’s process resulted in complete chlorophenol removal in 8 min, whereas solar catalysis resulted in degradation of the toxicant within 315 min, albeit slightly longer than UV-driven catalysis. Hence, solar processes can be considered as an environmentally friendly approach for treating industrial wastewater. Furthermore, the toxicity analysis conducted for treated effluent using a macrophyte reported the disruption of plant tissues and ultimately plant death, signifying the presence of chemical species obstructing the plant metabolism and growth.