An innovative method for environmental remediation using sparks formed during plasma electrolytic oxidation on aluminum foils

Abstract

This study explores the sparks formed during Plasma Electrolytic Oxidation (PEO) as an innovative method for the degradation of pharmaceutical pollutants. The proposed method achieves complete carbonization of the contaminants, transforming them entirely into CO2. This unique capability addresses a significant gap in existing literature, where degradation methods often halt at partial mineralization, leaving behind potentially harmful organic residues. By utilizing high-energy plasma generated on the electrode surface, our approach achieves rapid, full degradation without the need for any added oxidizing agents, aligning with green chemistry principles. Beginning with 0.35 ppm of ofloxacin (OFX), 1 ppm of sodium diclofenac (DCF), and 1 ppm of fluoxetine (FLX), the degradation was examined both individually and in a mixed-contaminant system. In single-contaminant systems, PEO achieved 50% removal of OFX and DCF and over 90% removal of FLX after 60 min, with complete conversion to CO2 in each case without the formation of any byproducts. In the mixture, the degradation efficiency improved further, resulting in 58% removal of DCF, 60% of OFX and 93% of FLX. This study’s results underscore the capacity of PEO to effectively degrade pharmaceutical pollutants across a range of concentrations found in real-world scenarios, offering a viable, sustainable solution for aqueous environments.