Metronidazole Degradation by UV and UV/H2O2 Advanced Oxidation Processes

Kinetics, Mechanisms, and Effects of Natural Water Matrices

Bibliographic Data

ID15470665
AuthorsRongkui Su (0000-0002-9830-6176, Central South University of Forestry and Technology), Xiangrong Dai (PowerChina (China)), Hanqing Wang (0009-0003-1898-1249, Central South University of Forestry and Technology), Zhixiang Wang (0000-0001-5815-3032, Central South University of Forestry and Technology), Zishi Li (Central South University of Forestry and Technology), Yonghua Chen (0000-0002-4588-8790, Central South University of Forestry and Technology), Yiting Luo (0009-0001-8557-9765, Hunan First Normal University, corresponding author), Danxia Ouyang (Central South University of Forestry and Technology)
Year2022
Volume19
Issue19
Pages12354-12354
Publication date2022-09-28
Peer ReviewedYes
Open AccessYes
TypeARTICLE
VenueInternational Journal of Environmental Research and Public Health (JOURNAL)
Journal identifiersISSN: 1661-7827 • E-ISSN: 1660-4601
PublisherMultidisciplinary Digital Publishing Institute (PUBLISHER • CH)
DOI10.3390/ijerph191912354
PMID36231654
OpenAlexW4297486384
LanguageEN
References cited71

Advanced oxidation technology represented by hydroxyl radicals has great potential to remove residual antibiotics. In this study, we systematically compared the metronidazole (MTZ) degradation behavior and mechanism in the UV and UV/H 2 O 2 systems at pH 3.00 condition. The results show that the initial reaction rates were 0.147 and 1.47 μM min -1 in the UV and UV/H 2 O 2 systems, respectively. The main reason for the slow direct photolysis of MTZ is the relatively low molar absorption coefficient (2645.44 M -1 cm -1 ) and quantum yield (5.9 × 10 -3 mol Einstein -1 ). Then, we measured kMTZ,OH • as 2.79 (±0.12) × 10 9 M -1 s -1 by competitive kinetics, and calculated kMTZ,OH • and [OH •]SS as 2.43 (±0.11) × 10 9 M -1 s -1 and 2.36 × 10 -13 M by establishing a kinetic model based on the steady-state hypothesis in our UV/H 2 O 2 system. The contribution of direct photolysis and • OH to the MTZ degradation was 9.9% and 90.1%. • OH plays a major role in the MTZ degradation, and • OH was the main active material in the UV/H 2 O 2 system. This result was also confirmed by MTZ degradation and radicals' identification experiments. MTZ degradation increases with H 2 O 2 dosage, but excessive H 2 O 2 had the opposite effect. A complex matrix has influence on MTZ degradation. Organic matter could inhibit the degradation of MTZ, and the quenching of the radical was the main reason. NO3- promoted the MTZ degradation, while SO42- and Cl - had no effect. These results are of fundamental and practical importance in understanding the MTZ degradation, and to help select preferred processes for the optimal removal of antibiotics in natural water bodies, such as rivers, lakes, and groundwater

Degradation (telecommunications · Kinetics · Metronidazole · Natural organic matter · Organic matter · Photochemistry · Physics · Advanced oxidation water treatment · Chemical Engineering · Chemistry · Computer Science · Environmental Science · Pharmaceutical and Antibiotic Environmental Impacts · Water Quality Monitoring and Analysis · Biochemistry · Environmental Chemistry · Organic Chemistry

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