Degradation of chlorpyrifos and deltamethrin by ultrasound and cold plasma: Process optimization and energy efficiency analysis

The increasing contamination of aquatic environments by pesticides, specifically organophosphates and pyrethroids, demands the development of efficient, sustainable remediation technologies. This study presents a comparative analysis of four non-thermal technologies (corona, glow, and dielectric barrier discharge (DBD) plasmas, and ultrasound) for the degradation of chlorpyrifos and deltamethrin in water. This research offers a novel evaluation of mechanical (acoustic cavitation) versus electrical (plasma) energy sources, integrating degradation levels, energy efficiency, and in vivo toxicological validation. The results demonstrated that all investigated technologies were effective, achieving removal rates up to 99.7%. Ultrasound was the most efficient method, reaching >99% removal of the pesticides within 3 minutes at a power density of 3125 W/L. Among the plasma systems, glow discharge achieved consistent high performance (>97% removal) across all operating conditions but was the most energy-intensive. The DBD plasma was the most energy-efficient technology, despite exhibiting frequency-dependent selectivity for the pesticides. The toxicological assays using the zebrafish model confirmed the biological safety of the treated effluents. These findings demonstrate that these non-thermal technologies efficiently degrade chlorpyrifos and deltamethrin and do not form toxic by-products, offering a technically viable solution for water treatment.