Degradation and mineralization of ciprofloxacin by gas–liquid discharge non-thermal plasma

Abstract

A typical quinolones antibiotic ciprofloxacin (CIP) in aqueous solution was degraded by a gasliquid discharge non-thermal plasma system. The discharge plasma power and the emission intensity of the excited reactive species (RS) generated in the gas phase were detected by the oscilloscope and the optical emission spectroscopy. The effects of various parameters on CIP degradation, i.e. input powers, initial concentrations addition of radical scavengers and pH values were investigated. With the increase of discharge power, the degradation efficiency increased but the energy efficiency significantly reduced. The degradation efficiency also reduced under high concentration of initial CIP conditions due to the competitive reactions between the plasma-induced RS with the degradation intermediates of CIP. Different radical scavengers (isopropanol and CCl 4 ) on •OH and H• were added into the reaction system and the oxidation effects of •OH radicals have been proved with high degradation capacity on CIP. Moreover, the long-term degradation effect on CIP in the plasma-treated aqueous solution proved that the long-lived RS (H 2 O 2 and O 3 , etc) might play key roles on the stay effect through multiple aqueous reactions leading to production of •OH. The degradation intermediates were determined by the method of electrospray ionization (+)-mass spectroscopy, and the possible degradation mechanism were presented.

Degradation of glucocorticoids in water by dielectric barrier discharge and dielectric barrier discharge combined with calcium peroxide: performance comparison and synergistic effects

“…This temperature rise possibly led to the quenching of the radicals, consequently decreasing the energy yield in DBD system. A similar energy yield (0.2–7.3 mg kW −1 h −1 ) also was reported by Hu et al, when using a nonthermal plasma reactor to degrade ciprofloxacin in aqueous solution. The energy yield of contaminant removal by DBD treatment in the present study was higher than that by photocatalysis with TiO 2 (1.8 mg kW −1 h −1 ) and catalytic plasma in a tubular reactor (0.24 mg kW −1 h −1 ) implying that this DBD plasma system could be a useful tool for GC removal.…”

Removal of emerging contaminants from wastewater using advanced treatments. A review

“…This discharge geometry, with one or several hollow needles submerged in liquid as high voltage electrode and plasma produced in gas bubbles at the tip of the needles, has been employed by several research groups for the removal of antibiotics, mostly in combination with catalysts (Wang et al 2018d;Guo et al 2019aGuo et al , 2019bGuo et al , 2019c. A slightly different configuration, with the gas blown through a tube containing the high voltage needle electrode, has also been used (He et al 2014(He et al , 2015Hu et al 2019). Several authors produce plasma in the gas and bubble the effluent gas through the solution to be treated (Kim et al 2013(Kim et al , 2015Lee et al 2018;Tang et al 2018aTang et al , 2018bTang et al , 2019Wang et al 2019c;Li et al 2020a).…”

Remediation of Emerging Contaminants

“…This discharge geometry, with one or several hollow needles submerged in liquid as high voltage electrode and plasma produced in gas bubbles at the tip of the needles, has been employed by several research groups for the removal of antibiotics, mostly in combination with catalysts (Wang et al 2018d;Guo et al 2019a, b, c). A slightly different configuration, with the gas blown through a tube containing the high voltage needle electrode has also been used (He et al 2014(He et al , 2015Hu et al 2019). Several authors produce plasma in the gas and bubble the effluent gas through the solution to be treated (Kim et al 2013;Kim et al 2015;Lee et al 2018;Tang et al 2018aTang et al , b, 2019Wang et al 2019c;Li et al 2020).…”