Aqueous Metronidazole Degradation by UV/H₂O₂ Process in Single-and Multi-Lamp Tubular Photoreactors: Kinetics and Reactor Design

Abstract

A kinetic model was developed to predict the removal of aqueous metronidazole utilizing the UV/H2O2 process. The rate constant for the reaction between metronidazole and hydroxyl radicals was determined to be 1.98 × 109 M−1 s−1. The model was able to predict an optimal initial H2O2 dose and the inhibitory effects of high H2O2 doses and bicarbonate ions in the aqueous solution. Simulations were performed for three different photoreactors treating a 6 μM solution of metronidazole at various influent H2O2 doses and photoreactor radii. The predicted removal rates of metronidazole were 4.9−13% and 14−41% for the single-lamp and multilamp photoreactors, respectively. Selection of a photoreactor radius for maximum metronidazole removal varied with influent H2O2 concentration. The lowest operational cost of $0.05 per mmol removed was projected for the multilamp photoreactor. Operationally, it was cost-effective to utilize higher UV lamp output (36W), while keeping influent H2O2 concentration low (25 mg/L).

Facile synthesis and high activity of novel BiVO4/FeVO4 heterojunction photocatalyst for degradation of metronidazole

“…Many technologies were reported to degrade metronidazole present in environmental waters, including ultraviolet (UV) irradiation [42] and oxidation processes using UV, UV/H 2 O 2 , H 2 O 2 /Fe 2+ , UV/H 2 O 2 /Fe 2+ , UV/Zn 2 GeO 4 [43]. In general, these processes are expensive and complicated [44,45]. In comparison, visible light irradiation is more easy to obtain and more cost-effective [46].…”

Metronidazole Removal Methods from Aquatic Media: A Systematic Review

“…For example, the oxidation process based on ozone causes decomposition of bromide to bromate ion suspected carcinogen and needs exhaust gas purification and flotation of volatile organic carbon. This is while these problems did not exist through replacing the UV rays rather than ozone in the UV/H 2 O 2 to remove organic pollutants (10).…”

Green Synthesis of Silver Nanoparticles by Mint Leaves: A Suitable Catalyst for Oxidation of Metronidazole

“…The C-H stretching frequency arises at around 2924. 15 Kinetic study for oxidation of metronidazole by hexacyanoferrate in the presence and absence of nanosilver catalyst: The progress of reaction was followed spectrophotometrically by monitoring absorbance of unreacted hexacyanoferrate in the reaction mixture at the λmax i.e. 410 nm, as a function of time (Figs.…”

“…In recent years, metronidazole is being widely used because of its pharmaceutical significance as well as its veterinary use. It is an antiprotozoal drug of nitroimidazole derivative having activity against anaerobic bacteria and protozoans [13][14][15]. This compound is highly hazardous, if exposed in the environment owing to its carcinogenic and mutagenic nature and found as a persistent toxic waste and is frequently used for the protozoal infection [16][17][18].…”