Degradation of metronidazole by radio frequency discharge in an aqueous solution

Abstract

Degradation of metronidazole (MNZ) by radio frequency discharge in water was examined. Results showed that • OH, H • , and • O were produced. Decay of MNZ followed pseudo-first order kinetics, where the apparent rate constant was independent of its initial concentration in the range 0-0.5 mM, decreased in the range 0.5-1.0 mM, and leveled off in the range higher than 1.0 mM. pH had no effects on MNZ degradation. • OH scavengers enhanced the MNZ removal. Formic acid, nitrite ion, oxalic acid, nitrate ion, and acetic acid were determined as the primary intermediate byproducts. The eventual products were ammonia and inorganic carbon. Both • OH and H • participated in the MNZ degradation. H • played more efficient role than • OH in the early stage.

Exploring the use of carbon materials as cathodes in electrochemical advanced oxidation processes for the degradation of antibiotics

“…It should be noted that after the treatment of both antibiotics in the real wastewater, the amount of nitrates in the effluent increased, reaching values of 10.3 and 9.1 mg L -1 for metronidazole and sulfamethoxazole, respectively (initial value 8.2 mg L -1 , Table 1). This points out to the release of nitrates during the degradation of the antibiotics, which is in agreement with the degradation mechanisms proposed for both compounds in the literature [42,43,52,55].…”

“…The amounts of those carboxylic acids detected during the AO and EF treatments on the studied carbons are represented in Figure 3. The identified organic acids are in line with those reported in the literature for the degradation of metronidazole by other oxidation techniques [42,43].…”

Quantification of plasma produced OH radical density for water sterilization

“…Low‐temperature atmospheric‐pressure plasmas can be used to sustainable degradation of pharmaceutical compounds, improving aerobic respiration of activated sludge, and induce specific biological effects in prokaryotic and eukaryotic cells with high efficiency, which is inherently linked to the rich assortment of highly‐reactive chemical species that are generated as a result of plasma treatment. Species produced in the plasma gas phase are short‐lived and highly‐chemically reactive.…”

Degradation of tiamulin by a packed bed dielectric barrier plasma combined with TiO2 catalyst

“…At the same time, in the plasma discharge process gas molecules are ionized and excited under the action of a strong electric field. When the excited particles produced by ionization recombine or transition from the excited state to a lower energy level or ground state, a large amount of light energy radiates out, which also stimulates TiO 2 to generate electron-hole pairs [22]. Specifically, the working gas generally contains a small amount of moisture and various trace gases in addition to oxygen and nitrogen.…”