Advanced water purification through sequential hybrid CoOx catalytic ozonation and electrocoagulation for effective contaminant removal and toxicity reduction

In response to the growing need for sustainable water-reuse solutions, this study focuses on optimizing wastewater treatment technologies to address contaminants of emerging concern (CECs). Advanced oxidation processes (AOPs) are explored as a key approach for removing pollutants, including the insecticide imidacloprid (IMI), the antibiotic sulfamethoxazole (SMX), and the endocrine disruptor butylparaben (BuP). The research investigates the use of thin-film nanocatalysts, deposited via cold plasma onto structured supports, to enhance catalytic ozonation efficiency. Hybrid technologies combining catalytic ozonation with electrocoagulation were evaluated against standalone methods such as single ozonation and electrochemical processes. The results indicate that the hybrid systems significantly outperform individual treatments, achieving greater pollutant degradation, mineralization, and toxicity reduction. The integration of CoO x thin films with Fe-electrocoagulation enhances process efficiency by overcoming the limitations of single methods and improving the conversion of organic pollutants into biodegradable intermediates. This study presents a novel sequential process combining plasma-enhanced CoO x catalytic ozonation with iron- and aluminum-based electrocoagulation, offering the first integrated assessment of oxidation state shifts and ecotoxicity reduction for a mixture of CECs marking a significant step toward safer and more efficient wastewater reuse. These innovative technologies support global environmental goals and align with the priorities of the Green Deal.