Activating peroxides to produce active substances is the key to advanced oxidation processes (AOPs), but this usually requires energy or is accompanied by additional contaminants. In this study, diclofenac (DCF) was effectively removed by peracetic acid (PAA) in phosphate buffer (PBS). According to the results of radical scavenging experiments and electron paramagnetic resonance (EPR), hydroxyl radical (•OH) and organic radicals (i.e., CHC(=O)OO• and CHC(=O)O•) generated from PBS-activated PAA might be the dominant reactive species responsible for DCF degradation. At neutral pH, PBS/PAA system exhibited the best degradation efficiency on DCF. Presence of NO, SO and Cl had little effect on the removal of DCF, while HCO and natural organic matter (NOM) significantly inhibited DCF degradation in PBS/PAA system, resulting in the lower degradation efficiency of DCF in natural waters than that in ultrapure water. Finally, four possible degradation pathways, including hydroxylation, formylation, dehydrogenation and dechlorination, were proposed based on the detected reaction products. This study suggests that PBS used to control solution pH should be applied cautiously in PAA-based AOPs.
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http://dx.doi.org/10.1016/j.chemosphere.2021.132396 | DOI Listing |
Water Res
December 2024
State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, China. Electronic address:
The integration of membrane separation with heterogeneous advanced oxidation processes is a prospective strategy for the elimination of contaminants during wastewater treatment. Fe-based catalysts and the green oxidant peracetic acid (PAA) are desirable candidates for the development of catalytic membranes because they are environmentally friendly. However, the construction of catalytic ceramic membranes (CMs) modified with efficient Fe-based catalysts that generate increased amounts of high-valent Fe-O species during PAA activation for the degradation of specific pollutants, especially during instantaneous membrane filtration, remains challenging.
View Article and Find Full Text PDFJ Hazard Mater
December 2024
State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu, Sichuan 610065, China; School of Architecture and Environment, Sichuan University, Chengdu 610065, China. Electronic address:
Selective oxidation relying on high-valent iron-oxo species (Fe(IV/V)) is a promising way of effective organic decontamination. However, Fe(IV/V) formation and further purposeful reinforcement production are commonly insufficient and unsustainable. Herein, cerium (Ce) modification strategy was adopted for efficient micropollutants removal through boosting Fe(IV/V) generation.
View Article and Find Full Text PDFJ Hazard Mater
December 2024
School of Environment, Beijing Normal University, No.19, Xinjiekouwai Street, Haidian District, Beijing 100875, China. Electronic address:
Sulfonamides (SAs) are one of the major emerging contaminants of concern, but comparative studies on the degradation of different types of SAs are still limited. This work comprehensively compared the degradation of sulfadiazine (SDZ), sulfamethoxazole (SMX) and sulfathiazole (STZ) under UV light in peracetic acid (PAA) from both experimental and theoretical aspects, as they represent two structural classes based on substituent differences. The two SAs with five-membered heterocyclic substituents (SMX, STZ) generally decomposed at faster rates, with SMX degrading up to 10 times faster than SDZ (pH = 3; PAA dosage = 80 mg/L).
View Article and Find Full Text PDFWater Res
December 2024
School of Environment Nanjing University, Nanjing 210023, Jiangsu Province, PR China. Electronic address:
The efficient removal of emerging micropollutants poses significant challenges in wastewater treatments. Advanced oxidation processes (AOPs) are extensively studied in the field, and peracetic acid (PAA) has attracted great attention as an alternative oxidant in recent years. Various reactive species yield in PAA-based AOPs, which are regarded as the promising approaches for pollutants elimination.
View Article and Find Full Text PDFJ Clin Exp Dent
November 2024
DDS, PhD. Professor, Center for Dental Medicine, Clinic for Masticatory Disorders and Dental Biomaterials, University of Zurich, Zurich, Switzerland.
Background: Ultraviolet C (UVC) light is a physical method proposed for disinfecting dental impression materials and preventing cross-infections in clinical practice. The investigations have focused on the UVC disinfection potential, but little is known about the consequences on dental materials' properties. This scoping review's objective is to evaluate information about the effect of UVC light on the dimensional stability of dental impression materials.
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