Recently, the combination of peroxymonosulfate (PMS) and hydroxylamine (HA) has been proposed as a green and efficient sulfate radical ()-based advanced oxidation process (AOP) for eliminating organic contaminants. However, we found that toxic nitrosated and nitrated aromatic compounds were generated during the treatment of phenolic compounds by PMS/HA system, indicating the involvement of reactive nitrogen species (RNS) during the interaction of PMS with HA. Specifically, considerable production of p-nitrosophenol (p-NSP) and mononitrophenol were obtained when phenol was oxidized by PMS/HA system under various conditions. At the molar ratio between HA and PMS of 1.0 and pH 5.0, sum of the yields of p-NSP and nitrophenols reached their maxima (around 50%). Moreover, production of p-NSP was inhibited while that of nitrophenols was promoted when applied NHOH1/2HSO was replaced by NHOHHCl, which was possibly related to the formation of secondary reactive species induced by the reaction of with chloride ion. Further, formation of undesirable nitrosated and nitrated aromatic products was obtained in the treatment of other phenolic compounds including acetaminophen, bisphenol A, and bisphenol S by PMS/HA system. Considering the toxicity of nitrosated and nitrated aromatic compounds, practical application of PMS/HA system for environmental decontamination should be scrutinized.
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http://dx.doi.org/10.1016/j.chemosphere.2021.131057 | DOI Listing |
BMC Neurosci
December 2024
Department of Anatomy, Faculty of Basic Medical Sciences, University of Ibadan, Ibadan, Oyo State, Nigeria.
Diethylnitrosamine (DEN), a common dietary carcinogen, is associated with neurotoxicity in humans and animals. This study investigated the neuroprotective effects of diphenyl diselenide (DPDS) against DEN-induced neurotoxicity in male Albino Wistar rats (n = 40). Rats were randomly distributed into cohorts and treated as follows: vehicle control (corn oil 2 mL/kg; gavage), DPDS-only (5 mg/kg; gavage) and DEN-only (200 mg/kg; single dose i.
View Article and Find Full Text PDFJ Hazard Mater
December 2024
Key Laboratory of Eco-Environments in Three Gorges Reservoir Region, Ministry of Education, College of Environment and Ecology, Chongqing University, Chongqing 400045, PR China.
Carbonate radical (CO) is inevitably produced in advanced oxidation processes (AOPs) when addressing real-world aqueous environments, yet it often goes unnoticed due to its relatively lower reactivity. In this study, we emphasized the pivotal role of CO in targeting the elimination of contaminants by contrasting it with conventional reactive oxygen species (ROSs) and assessing the removal of sulfamethazine (SMT). Similar to singlet oxygen (O), CO shows a preference for electron-rich organic compounds.
View Article and Find Full Text PDFFree Radic Biol Med
December 2024
Dept. of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark. Electronic address:
Water Res
November 2024
Department of Environmental Science and Engineering, Nanjing Agricultural University, Nanjing 210095, China. Electronic address:
Sulfate radical (SO) advanced oxidation processes (SR-AOPs) are efficient for degrading a broad spectrum of contaminants. This study demonstrates that the existence of environmentally relevant concentrations of nitrite (NO) can lead to the formation of N-nitrosodimethylamine (NDMA), a probable human carcinogen, when heat activated peroxydisulfate (heat/PDS) is applied to address contaminants with dimethylamine moieties, such as tetracyclines. NO effectively competes with tetracyclines for SO at a high second-order reaction rate constant of 8.
View Article and Find Full Text PDFSci Total Environ
December 2024
College of Environmental Science and Engineering, Donghua University, 2999 North Renmin Road, Shanghai 201620, China; Shanghai institute of pollution control and ecological security, Shanghai 200092, China. Electronic address:
The ubiquitous presence of sulfonamides (SAs) in wastewater poses serious risks to human health and ecosystem safety. This study evaluated the performance of a falling film dielectric barrier discharge (DBD) system on the removal of five SAs, namely sulfamethoxazole (SMX), sulfisoxazole (SIZ), sulfathiazole (STZ), sulfadiazine (SDZ) and sulfamerazine (SMR). Removal efficiencies >99 % were observed for all target SAs within 30 min of treatment, with pseudo-first order rate constants varying between 0.
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