Heterogeneous Photocatalysis of Metronidazole in Aquatic Samples

Abstract

Metronidazole (MET) is a commonly detected contaminant in the environment. The compound is classified as poorly biodegradable and highly soluble in water. Heterogeneous photocatalysis is the most promoted water purification method due to the possibility of using sunlight and small amounts of a catalyst needed for the process. The aim of this study was to select conditions for photocatalytic removal of metronidazole from aquatic samples. The effect of catalyst type, mass, and irradiance intensity on the efficiency of metronidazole removal was determined. For this purpose, TiO2, ZnO, ZrO2, WO3, PbS, and their mixtures in a mass ratio of 1:1 were used. In this study, the transformation products formed were identified, and the mineralization degree of compound was determined. The efficiency of metronidazole removal depending on the type of catalyst was in the range of 50–95%. The highest MET conversion (95%) combined with a high degree of mineralization (70.3%) was obtained by using a mixture of 12.5 g TiO2–P25 + PbS (1:1; v/v) and running the process for 60 min at an irradiance of 1000 W m−2. Four MET degradation products were identified by untargeted analysis, formed by the rearrangement of the metronidazole and the C-C bond breaking.

Considerations on the Controlled Delivery of Bioactive Compounds through Hyaluronic Acid Membrane

“…The third bioactive component used, MZ, undergoes hydrolysis reaction, in presence of hydroxyl radicals [ 84 ]. Therefore, it is important to follow the behavior of MZ solution at various pH values.…”

Thermoresponsive polymer brush photocatalytic substrates for wastewater remediation

“…33,[39][40][41][42][43][44] Despite their promise, only a few limited examples of multiresponsive organic heterocatalytic photoactive materials exist. 43,45 Their limitations include inadequate solubility 46,47 or limited synthetic versatility. For polymer-based photocatalysts, separating a synthetic product the photocatalytic polymer often remains prohibitively challenging.…”

Review of Analytical Methodologies for the Determination of Metronidazole and Trimethoprim in Environmental Samples

“…The combination of 12.5 g TiO2-P25 + PbS (1:1; v/v) yielded the highest MET conversion (95%) when the process was run for 60 minutes at 1000 W m−2. Untargeted analysis revealed the identification of four MET degradation products, which resulted from metronidazole rearrangement and C-C bond breaking [47]. Two straightforward, quick, inexpensive, and reliable chromatographic methods were presented and approved for use in the quantitative assessment of MET residues in samples of production wastewater.…”