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The increasing global water demand has prompted the reuse of treated wastewater. However, the persistence of organic micropollutants in inefficiently treated effluents can have detrimental effects depending on the scope of the reclaimed water usage. One example is the presence of sulfamethoxazole, a widely used antibiotic whose interference with the folate synthesis pathway negatively affects plants and microorganisms. The goal of this study is to assess the suitability of a non-thermal plasma-ozonation technique for the removal of the organic pollutant and reduction of its herbicidal effect. Fast sulfamethoxazole degradation was achieved with apparent reaction rate constants in the range 0.21-0.49 min -1 , depending on the initial concentration. The highest energy yield (64.5 g/kWh at 50 % removal) exceeds the values reported thus far in plasma degradation experiments. During treatment, 38 degradation intermediates were detected and identified, of which only 9 are still present after 60 min. The main reactive species that contribute to the degradation of sulfamethoxazole and its intermediate products were hydroxyl radicals and ozone, which led to the formation of several hydroxylated compounds, ring opening and fragmentation. The herbicidal effect of the target compound was eliminated with its removal, showing that the remanent intermediates do not retain phytotoxic properties., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier B.V.)

Large amounts of antibiotics are produced and consumed worldwide, while wastewater treatment is still rather inefficient, leading to considerable water contamination. Concentrations of antibiotics in the environment are often sufficiently high to exert a selective pressure on bacteria of clinical importance that increases the prevalence of resistance. Since the drastic reduction in the use of antibiotics is not envisaged, efforts to reduce their input into the environment by improving treatment of contaminated wastewater is essential to limit uncontrollable spread of antibiotic resistance. This paper reviews recent progress on the use of non-thermal plasma for the degradation of antibiotics in water. The target compounds removal, the energy efficiency and the mineralization are analyzed as a function of discharge configuration and the most important experimental parameters. Various ways to improve the plasma process efficiency are addressed. Based on the identified reaction intermediates, degradation pathways are proposed for various classes of antibiotics and the degradation mechanisms of these chemicals under plasma conditions are discussed., (Copyright © 2021 Elsevier B.V. All rights reserved.)

A novel advanced oxidation process based on the combination of ozonation with non-thermal plasma generated in a pulsed corona discharge was developed for the oxidative degradation of recalcitrant organic pollutants in water. The pulsed corona discharge in contact with liquid, operated in oxygen, produced 3.5mgL -1 ozone, which was subsequently introduced in the ozonation reactor. The solution to be treated was continuously circulated between the plasma reactor and the ozonation reactor. The system was tested for the degradation of 2,4-dichlorophenoxyacetic acid (2,4-D) and considerably improved performance as compared to ozonation alone, both with respect to the removal of the target compound and to mineralization. The apparent reaction rate constant for 2,4-D removal was 0.195min -1 , more than two times higher than the value obtained in ozonation experiments. The mineralization reached more than 90% after 60min treatment and the chlorine balance confirms the absence of quantifiable amounts of chlorinated by-products. The energy efficiency was considerably enhanced by shortening the duration of the discharge pulses, which opens the way for further optimization of the electrical circuit design., (Copyright © 2017 Elsevier B.V. All rights reserved.)