The Experts below are selected from a list of 357 Experts worldwide ranked by ideXlab platform
Jeanmarc Chovelon - One of the best experts on this subject based on the ideXlab platform.
-
non activated peroxymonosulfate oxidation of sulfonamide antibiotics in water kinetics mechanisms and implications for water treatment
Water Research, 2018Co-Authors: Lu Wang, Corinne Ferronato, Mengdi Jiang, Yan Yang, Peizeng Yang, Lei Zhou, Jeanmarc ChovelonAbstract:Despite that sulfate radical-based activated peroxymonosulfate (PMS) oxidation processes (e.g., UV/PMS, Co2+/PMS, etc.) have been widely applied for decontamination, the direct oxidation of organic contaminants by PMS per se is less known. This contribution reports that certain contaminants, such as sulfonamides (SAs), are amendable to direct oxidation by PMS without activation. Using sulfamethoxazole (SMX) as a representative, kinetics and density functional theory (DFT)-based computational methods were applied to elucidate the underlying mechanisms and pathways through which SMX was transformed by direct PMS oxidation. High resolution mass spectrometry (HR-MS) coupled with high performance liquid chromatography (HPLC) analyses using authentic standards were adopted to qualifying and quantifying SMX transformation products. Our results reveal that nonradical oxidation of SMX by PMS was initiated by formation of a transition state complex between PMS molecule and amino functional group of SMX. Such reaction was assisted by two water molecules, which significantly reduced energy barrier. Direct PMS oxidation of SMX led to the formation of N4-hydroxyl-sulfamethoxazole (N4-OH-SMX), 4-nitroso-sulfamethoxazole (4-NO-SMX), and 4-nitro-sulfamethoxazole (4-NO2-SMX), sequentially. Implications of PMS oxidation with SAs to water treatment were further evaluated by investigating the effects of PMS dosage, pH, and natural water matrices. While PMS has a potential to transform a suite of SAs with similar structures (SMX, sulfisoxazole, sulfamethizole, sulfapyridine, sulfadiazine, and sulfachloropyridazine), the formation of potential hazardous nitroso- and nitro-byproducts should be scrutinized before this technology can be safely used for water and wastewater treatment.
-
sulfate radical based oxidation of antibiotics sulfamethazine sulfapyridine sulfadiazine sulfadimethoxine and sulfachloropyridazine formation of so2 extrusion products and effects of natural organic matter
Science of The Total Environment, 2017Co-Authors: Yuefei Ji, Lu Wang, Junhe Lu, Corinne Ferronato, Jeanmarc ChovelonAbstract:The widespread occurrence of sulfonamide antibiotics in the environment has raised great concerns about their potential to proliferate antibacterial resistance. Sulfate radical (SO4•-) based advanced oxidation processes (SR-AOPs) are promising in-situ chemical oxidation (ISCO) technologies for remediation of soil and groundwater contaminated by antibiotics. The present study reported that thermally activated persulfate oxidation of sulfonamides (SAs) bearing six-membered heterocyclic rings, e.g., sulfamethazine (SMZ), sulfapyridine (SPD), sulfadiazine (SDZ), sulfadimethoxine (SDM), and sulfachloropyridazine (SCP), all produced SO2 extrusion products (SEPs), a phenomenon that is of potential importance, but not systematically studied. As an electrophilic oxidant, SO4•- tends to attack the aniline moiety, the reactive site of SAs, via electro-transfer mechanism. The resulting anilinyl radical cations are subjected to further intermolecular Smiles-type rearrangement to produce SEPs. Formation of SEPs is expected to occur in other SR-AOPs as well. The temperature-dependent evolution pattern of SEP of SMZ, 4-(2-imino-4,6-dimethylpyrimidin-1(2H)-yl)aniline, can be well fitted by kinetic modeling concerning sequential formation and transformation of intermediate product. The presence of natural organic matter (NOM) influenced the evolution patterns of 4-(2-imino-4,6-dimethylpyrimidin-1(2H)-yl)aniline significantly. Toxicological effects of SEPs on ecosystem and human health remain largely unknown, thus, further monitoring studies are highly desirable.
-
sulfate radical based oxidation of antibiotics sulfamethazine sulfapyridine sulfadiazine sulfadimethoxine and sulfachloropyridazine formation of so 2 extrusion products and effects of natural organic matter
Science of The Total Environment, 2017Co-Authors: Yuanyuan Shi, Lu Wang, Corinne Ferronato, Jeanmarc ChovelonAbstract:The widespread occurrence of sulfonamide antibiotics in the environment has raised great concerns about their potential to proliferate antibacterial resistance. Sulfate radical (SO4•-) based advanced oxidation processes (SR-AOPs) are promising in-situ chemical oxidation (ISCO) technologies for remediation of soil and groundwater contaminated by antibiotics. The present study reported that thermally activated persulfate oxidation of sulfonamides (SAs) bearing six-membered heterocyclic rings, e.g., sulfamethazine (SMZ), sulfapyridine (SPD), sulfadiazine (SDZ), sulfadimethoxine (SDM), and sulfachloropyridazine (SCP), all produced SO2 extrusion products (SEPs), a phenomenon that is of potential importance, but not systematically studied. As an electrophilic oxidant, SO4•- tends to attack the aniline moiety, the reactive site of SAs, via electro-transfer mechanism. The resulting anilinyl radical cations are subjected to further intermolecular Smiles-type rearrangement to produce SEPs. Formation of SEPs is expected to occur in other SR-AOPs as well. The temperature-dependent evolution pattern of SEP of SMZ, 4-(2-imino-4,6-dimethylpyrimidin-1(2H)-yl)aniline, can be well fitted by kinetic modeling concerning sequential formation and transformation of intermediate product. The presence of natural organic matter (NOM) influenced the evolution patterns of 4-(2-imino-4,6-dimethylpyrimidin-1(2H)-yl)aniline significantly. Toxicological effects of SEPs on ecosystem and human health remain largely unknown, thus, further monitoring studies are highly desirable.
Shaobin Wang - One of the best experts on this subject based on the ideXlab platform.
-
nitrogen doped bamboo like carbon nanotubes with ni encapsulation for persulfate activation to remove emerging contaminants with excellent catalytic stability
Chemical Engineering Journal, 2018Co-Authors: Jian Kang, Hongqi Sun, Moses O. Tadé, Xiaoguang Duan, Chen Wang, Xiaoyao Tan, Shaobin WangAbstract:Abstract Nitrogen-doped bamboo-like carbon nanotubes encapsulated with nickel nanoparticles (Ni@NCNTs) were feasibly fabricated by a one-pot pyrolysis route. The characterization techniques revealed the surface morphology, structure and chemical composition of the as-prepared catalysts synthesized in different conditions. Ni@NCNTs were employed as both adsorbents and catalysts for activating persulfate to remove an emerging pollutant, antibiotic sulfachloropyridazine. The nitrogen modification enhanced both adsorption capacity and catalytic ability of Ni@NCNTs and proved to be a promising alternative to metal oxides and other carbon catalysts. Moreover, Ni@NCNTs showed an excellent stability because of nitrogen heteroatom doping and Ni nanoparticle encapsulation. Electron paramagnetic resonance (EPR) and classical radical quenching tests discovered a simultaneous radical/non-radical mechanism in Ni@NCNTs/persulfate system. The results indicated that the novel nano-architectured catalyst materials can show emerging functionalities for environmental remediation processes.
-
an insight into metal organic framework derived n doped graphene for the oxidative degradation of persistent contaminants formation mechanism and generation of singlet oxygen from peroxymonosulfate
Environmental science. Nano, 2017Co-Authors: Ping Liang, Moses O. Tadé, Xiaoguang Duan, Chi Zhang, Shaobin WangAbstract:The synthesis of carbonaceous materials from a metal organic framework (MIL-100), organic linker and N-precursor was comprehensively investigated, and the structures of the products were characterized. It was found that simple pyrolysis of mixed MIL-100 (Fe)/dicyandiamide (DCDA) could produce nitrogen-doped graphene (N-graphene). The N-graphene showed excellent performances in peroxymonosulfate (PMS) activation, which were superior to those of counterparts of graphene, iron(II, III) oxide, manganese(IV) oxide and cobalt(II, III) oxide. With PMS activation, N-graphene exhibited efficient catalytic degradation of various organic pollutants such as phenol, 2,4,6-trichlorophenol (TCP), sulfachloropyridazine (SCP) and p-hydroxybenzoic acid (PHBA). Electron paramagnetic resonance (EPR) spectroscopy and radical quenching tests were employed to investigate the PMS activation and organic degradation processes. It was found that singlet oxygen (1O2) was mainly produced during the activation of PMS by N-graphene, and contributed to the catalytic oxidation instead of sulfate and/or hydroxyl radicals. These findings provide new insights into PMS activation by metal-free carbon catalysis.
-
Excellent performance of copper based metal organic framework in adsorptive removal of toxic sulfonamide antibiotics from wastewater
Journal of colloid and interface science, 2016Co-Authors: Muhammad Rizwan Azhar, Hussein Rasool Abid, Hongqi Sun, Vijay Periasamy, Moses O. Tadé, Shaobin WangAbstract:The increasing concerns on toxicity of sulfonamide antibiotics in water require a prompt action to establish efficient wastewater treatment processes for their removal. In this study, adsorptive removal of a model sulfonamide antibiotic, sulfachloropyridazine (SCP), from wastewater is presented for the first time using a metal organic framework (MOF). A high surface area and thermally stable MOF, HKUST-1, was synthesized by a facile method. Batch adsorption studies were systematically carried out using HKUST-1. The high surface area and unsaturated metal sites resulted in a significant adsorption capacity with faster kinetics. Most of the SCP was removed in 15min and the kinetic data were best fitted with the pseudo second order model. Moreover, isothermal data were best fitted with the Langmuir model. The thermodynamic results showed that the adsorption is a spontaneous and endothermic process. The adsorption capacity of HKUST-1 is 384mg/g at 298K which is the highest compared to most of the materials for the antibiotics. The high adsorption capacity is attributed mainly to π-π stacking, hydrogen bonding and electrostatic interactions.
-
carbocatalytic activation of persulfate for removal of antibiotics in water solutions
Chemical Engineering Journal, 2016Co-Authors: Jian Kang, Hongqi Sun, Moses O. Tadé, Xiaoguang Duan, Li Zhou, Shaobin WangAbstract:Emerging pharmaceutical contaminants have raised severe challenges to remediation technologies for water treatment. In this paper, we report a facile method for preparation of nitrogen doped reduced graphene oxide (N-rGO) using urea as a nitrogen precursor. The prepared metal-free N-rGO is able to efficiently activate persulfate (PS) to produce reactive radicals for degradation of an antibiotic of sulfachloropyridazine (SCP). The effects of reaction parameters on SCP degradation were investigated. The activation processes were studied by in situ electron paramagnetic resonance (EPR), which discovered the newly observed hydroxyl radicals from PS activation. This study suggests a green remediation for removal of antibiotics in wastewater without producing any heavy metal leaching as the secondary contamination.
Alistair B.a. Boxall - One of the best experts on this subject based on the ideXlab platform.
-
prevalence of sulfonamide resistance genes in bacterial isolates from manured agricultural soils and pig slurry in the united kingdom
Antimicrobial Agents and Chemotherapy, 2009Co-Authors: K G Byrnebailey, William H. Gaze, Peter M Hawkey, Alistair B.a. Boxall, Elizabeth M. H. WellingtonAbstract:Prevalence of three sulfonamide resistance genes, sul1, sul2 and sul3 and sulfachloropyridazine (SCP) resistance was determined in bacteria isolated from UK manured agricultural clay soils and slurry samples, over a two year period. Slurry from tylosin-fed pigs amended with SCP and oxytetracycline (OTC) was used for manuring. Sul gene positive isolates were further screened for the presence of class 1 and 2 integrons. Phenotypic resistance to SCP was significantly higher in pig slurry and post application soil than in pre-application soil. Of 5isolates, 23 % carried sul1, 18 % sul2 and 9 % sul3 only. Two percent of isolates contained all three sul genes. Class 1 and class 2 integrons were identified in 5 % and 11.7 % of sul positive isolates. In previous reports, sul1 was linked to class 1 integrons, but in this study only 8 % of sul1 positive isolates carried the intI1 gene. Sulfonamide resistant pathogens were identified in slurry amended soil and soil leachate, including Shigella flexneri, Aerococcus spp. and Acinetobacter baumanni, suggesting a potential environmental reservoir. Sulfonamide resistance in Psychrobacter, Enterococcus and Bacillus spp. is reported for the first time, and this study also provides the first description of the genotype sul1, sul2 and sul3 outside the Enterobacteriacae, and in the soil environment.
-
Prevalence of sulfonamide resistance genes in bacterial isolates from manured agricultural soils and pig slurry in the United Kingdom
Antimicrobial Agents and Chemotherapy, 2009Co-Authors: Kathryne G. Byrne-bailey, Paul Kay, William H. Gaze, Peter M Hawkey, Alistair B.a. Boxall, Elizabeth M. H. WellingtonAbstract:The prevalences of three sulfonamide resistance genes, sul1, sul2, and sul3 and sulfachloropyridazine (SCP) resistance were determined in bacteria isolated from manured agricultural clay soils and slurry samples in the United Kingdom over a 2-year period. Slurry from tylosin-fed pigs amended with SCP and oxytetracycline was used for manuring. Isolates positive for sul genes were further screened for the presence of class 1 and 2 integrons. Phenotypic resistance to SCP was significantly higher in isolates from pig slurry and postapplication soil than in those from preapplication soil. Of 531 isolates, 23% carried sul1, 18% sul2, and 9% sul3 only. Two percent of isolates contained all three sul genes. Class 1 and class 2 integrons were identified in 5% and 11.7%, respectively, of sul-positive isolates. In previous reports, sul1 was linked to class 1 integrons, but in this study only 8% of sul1-positive isolates carried the intI1 gene. Sulfonamide-resistant pathogens, including Shigella flexneri, Aerococcus spp., and Acinetobacter baumannii, were identified in slurry-amended soil and soil leachate, suggesting a potential environmental reservoir. Sulfonamide resistance in Psychrobacter, Enterococcus, and Bacillus spp. is reported for the first time, and this study also provides the first description of the genotypes sul1, sul2, and sul3 outside the Enterobacteriaceae and in the soil environment.
-
the dissipation and transport of veterinary antibiotics in a sandy loam soil
Chemosphere, 2007Co-Authors: Paul A Blackwell, Paul Kay, Alistair B.a. BoxallAbstract:Abstract The environmental fate of the antibiotics sulfachloropyridazine and oxytetracycline was investigated in a sandy loam soil. Liquid pig manure was fortified with the compounds and then applied to soil plots to investigate leaching, dissipation and surface run-off under field conditions. Additionally, as the macrolide antibiotic tylosin had been administered to the pigs from which the slurry had been sourced, this was also analysed for in the samples collected. Sulfachloropyridazine dissipated rapidly with DT50 and DT90 values of 3.5 and 18.9 days but oxytetracycline was more persistent with DT50 and DT90 values of 21.7 and 98.3 days. Both sulfachloropyridazine and oxytetracyline were detected in surface run-off samples at maximum concentrations of 25.9 and 0.9 μg/l respectively but only sulfachloropyridazine was detected in soil water samples at a maximum concentration of 0.78 μg/l at 40 cm depth 20 days after treatment. Tylosin was not detected in any soil or water samples. The results indicated that tylosin, when applied in slurry, posed very little risk of accumulating in soil or contaminating ground or surface water. However, tylosin may pose a risk if used to treat animals on pasture and risks arising from transformation products of tylosin, formed during slurry storage, cannot be ruled out. Oxytetracycline posed a very low risk of ground or surface water contamination but had the potential to persist in soils and sulfachloropyridazine posed a moderate risk of contaminating ground or surface water but had low potential to accumulate in soils. These findings were consistent with the sorption and persistence characteristics of the compounds and support a number of broad-scale monitoring studies that have measured these antibiotic classes in the environment.
-
fast and robust simultaneous determination of three veterinary antibiotics in groundwater and surface water using a tandem solid phase extraction with high performance liquid chromatography uv detection
Journal of Chromatography A, 2004Co-Authors: Paul A Blackwell, Hanschristian Holten Lutzhoft, Bent Hallingsorensen, Alistair B.a. BoxallAbstract:Abstract A simple and robust analytical method is presented in which the three veterinary antibiotics oxytetracycline (OTC), sulfachloropyridazine (SCP) and tylosin (TYL) were simultaneously determined in surface water and groundwater. The three compounds were simultaneously extracted from the water samples using a mixture of methanol, EDTA and McIlvaine buffer (citric acid and sodium orthophosphate) and then cleaned-up and pre-concentrated by solid-phase extraction using sacrificial Isolute strong anion-exchange cartridges, to remove interfering organic material, and Waters Oasis hydrophilic–liphophilic balance polymer cartridges, to retain the compounds, in tandem. Analysis was performed using liquid chromatography with ultraviolet detection. Recoveries for river water samples spiked at 10 and 1 μg l−1 were respectively 99.6±4.6 and 99.4±8.4% for OTC; 99.9±2.2 and 105.0±5.7% for SCP; and 94.9±2.4 and 71.6±8.2% for TYL. Overall limits of detection based on pre-concentrating 400 ml of sample were 0.35 μg l−1 for OTC and TYL and 0.25 μg l−1 for SCP.
-
the sorption and transport of a sulphonamide antibiotic in soil systems
Toxicology Letters, 2002Co-Authors: Alistair B.a. Boxall, Paul Kay, Paul A Blackwell, Romina Cavallo, Johannes TollsAbstract:Veterinary medicines are administered to animals to treat disease and protect their health. After administration, the substances can be metabolised and a mixture of the parent compound and metabolites may be excreted in the urine and faeces. For animals on pasture, the excreta will be released directly to soil whereas for intensively reared animals, the main route of entry will be through slurry and manure spreading. Whilst the behaviour of other classes of substance (e.g. pesticides and nutrients) that are applied to soil is well understood, limited information is available on the transport and fate of veterinary medicines applied to soils. Laboratory and field studies were, therefore, performed to investigate the sorption behaviour of the sulfonamide antibiotic, sulfachloropyridazine, in soil and to assess the potential for sulfachloropyridazine to move from soil to surface waters and groundwaters. Sorption coefficients (KD) for the compound in soil and soil/slurry mixtures were low (ranging from 0.9 to 1.8 l kg−1) and indicated that the substance would be highly mobile. Field studies on a clay field supported these observations and demonstrated that, after application, the compound was rapidly transported to surface waters, concentrations of up to 590 μg l−1 being observed in drainage waters. Leaching studies at a sandy site indicated that the substance had a low potential to leach to groundwaters, concentrations in the soil pore water being below or close to analytical detection limits. An assessment of currently available models for predicting concentrations of veterinary medicines entering surface waters indicated that for sulfachloropyridazine, the methods provide reasonable estimates, predicted concentrations being within a factor of two of the maximum measured concentrations. The approaches may not, however, be appropriate for use on highly hydrophobic substances or for predicting groundwater concentrations.
Johannes Tolls - One of the best experts on this subject based on the ideXlab platform.
-
the effect of ph and ionic strength on the sorption of sulfachloropyridazine tylosin and oxytetracycline to soil
Environmental Toxicology and Chemistry, 2006Co-Authors: Thomas L Ter Laak, Johannes Tolls, Wouter A GebbinkAbstract:Antimicrobial agents are the most heavily used pharmaceuticals in intensive husbandry. Their usual discharge pathway is application to agricultural land as constituents of animal manure, which is used as fertilizer. Many of these compounds undergo pH-dependent speciation and, therefore, might occur as charged species in the soil environment. Hence, pH and ionic strength of the soil suspension can affect the sorption behavior of these compounds to soil. Consequently, the soil sorption of three antimicrobial agents--sulfachloropyridazine (SCP), tylosin (TYL), and oxytetracycline (OTC)--was investigated. Their respective sorption coefficients in two agricultural soils ranged from 1.5 to 1,800 L/kg. Sorption coefficients were greater under acidic conditions. Addition of an electrolyte to the solution led to decreased sorption of TYL and OTC by a factor of 3 to 20, but it did not influence the sorption of SCP. This behavior was analyzed by accounting for the pH-dependent speciation of TYL and OTC and considering the presence of OTC-calcium complexes. It appears that the decreased sorption of TYL and OTC with increasing ionic strength results from competition of the electrolyte cations with the positively charged TYL species and the positively charged OTC complexes. A model linking sorbate speciation with species-specific sorption coefficients can describe the pH dependence of the apparent sorption coefficients. This modeling approach is proposed for implementation in the assessment of sorption of ionizable compounds.
-
pollution induced community tolerance of soil microbial communities caused by the antibiotic sulfachloropyridazine
Environmental Science & Technology, 2004Co-Authors: Heike Schmitt, Johannes Tolls, Patrick Van Beelen, Cornelis L Van LeeuwenAbstract:Little is known about the environmental hazards linked to the treatment of farm animals with antibiotics and subsequent spreading of manure, especially regarding soil microbial communities. In this investigation, pollution-induced community tolerance (PICT) of bacteria from soils artificially spiked with the sulfonamide sulfachloropyridazine (SCP) was investigated. Tolerance of the bacterial communities after 3 weeks' exposure to SCP was determined by analyzing the sensitivity of 31 microbial metabolic processes in microtiter plates. Bacterial suspensions extracted from soils containing higher concentrations of SCP showed an increased tolerance of their metabolic activities to this antibiotic. An increase in tolerance by 10% was found at 7.3 mg/kg dw SCP. The PICT effect could be demonstrated by both a shift in the tolerance of the average of all metabolic activities and a shift of the physiological process sensitivity distributions made up from the single metabolic processes. The PICT effect was accompanied by smaller changes in the community-level physiological profile (CLPP). To conclude, PICT has been shown to be a versatile and illustrative method for the detection of the effects of antibacterial agents on soil microorganisms.
-
the sorption and transport of a sulphonamide antibiotic in soil systems
Toxicology Letters, 2002Co-Authors: Alistair B.a. Boxall, Paul Kay, Paul A Blackwell, Romina Cavallo, Johannes TollsAbstract:Veterinary medicines are administered to animals to treat disease and protect their health. After administration, the substances can be metabolised and a mixture of the parent compound and metabolites may be excreted in the urine and faeces. For animals on pasture, the excreta will be released directly to soil whereas for intensively reared animals, the main route of entry will be through slurry and manure spreading. Whilst the behaviour of other classes of substance (e.g. pesticides and nutrients) that are applied to soil is well understood, limited information is available on the transport and fate of veterinary medicines applied to soils. Laboratory and field studies were, therefore, performed to investigate the sorption behaviour of the sulfonamide antibiotic, sulfachloropyridazine, in soil and to assess the potential for sulfachloropyridazine to move from soil to surface waters and groundwaters. Sorption coefficients (KD) for the compound in soil and soil/slurry mixtures were low (ranging from 0.9 to 1.8 l kg−1) and indicated that the substance would be highly mobile. Field studies on a clay field supported these observations and demonstrated that, after application, the compound was rapidly transported to surface waters, concentrations of up to 590 μg l−1 being observed in drainage waters. Leaching studies at a sandy site indicated that the substance had a low potential to leach to groundwaters, concentrations in the soil pore water being below or close to analytical detection limits. An assessment of currently available models for predicting concentrations of veterinary medicines entering surface waters indicated that for sulfachloropyridazine, the methods provide reasonable estimates, predicted concentrations being within a factor of two of the maximum measured concentrations. The approaches may not, however, be appropriate for use on highly hydrophobic substances or for predicting groundwater concentrations.
Lu Wang - One of the best experts on this subject based on the ideXlab platform.
-
non activated peroxymonosulfate oxidation of sulfonamide antibiotics in water kinetics mechanisms and implications for water treatment
Water Research, 2018Co-Authors: Lu Wang, Corinne Ferronato, Mengdi Jiang, Yan Yang, Peizeng Yang, Lei Zhou, Jeanmarc ChovelonAbstract:Despite that sulfate radical-based activated peroxymonosulfate (PMS) oxidation processes (e.g., UV/PMS, Co2+/PMS, etc.) have been widely applied for decontamination, the direct oxidation of organic contaminants by PMS per se is less known. This contribution reports that certain contaminants, such as sulfonamides (SAs), are amendable to direct oxidation by PMS without activation. Using sulfamethoxazole (SMX) as a representative, kinetics and density functional theory (DFT)-based computational methods were applied to elucidate the underlying mechanisms and pathways through which SMX was transformed by direct PMS oxidation. High resolution mass spectrometry (HR-MS) coupled with high performance liquid chromatography (HPLC) analyses using authentic standards were adopted to qualifying and quantifying SMX transformation products. Our results reveal that nonradical oxidation of SMX by PMS was initiated by formation of a transition state complex between PMS molecule and amino functional group of SMX. Such reaction was assisted by two water molecules, which significantly reduced energy barrier. Direct PMS oxidation of SMX led to the formation of N4-hydroxyl-sulfamethoxazole (N4-OH-SMX), 4-nitroso-sulfamethoxazole (4-NO-SMX), and 4-nitro-sulfamethoxazole (4-NO2-SMX), sequentially. Implications of PMS oxidation with SAs to water treatment were further evaluated by investigating the effects of PMS dosage, pH, and natural water matrices. While PMS has a potential to transform a suite of SAs with similar structures (SMX, sulfisoxazole, sulfamethizole, sulfapyridine, sulfadiazine, and sulfachloropyridazine), the formation of potential hazardous nitroso- and nitro-byproducts should be scrutinized before this technology can be safely used for water and wastewater treatment.
-
sulfate radical based oxidation of antibiotics sulfamethazine sulfapyridine sulfadiazine sulfadimethoxine and sulfachloropyridazine formation of so2 extrusion products and effects of natural organic matter
Science of The Total Environment, 2017Co-Authors: Yuefei Ji, Lu Wang, Junhe Lu, Corinne Ferronato, Jeanmarc ChovelonAbstract:The widespread occurrence of sulfonamide antibiotics in the environment has raised great concerns about their potential to proliferate antibacterial resistance. Sulfate radical (SO4•-) based advanced oxidation processes (SR-AOPs) are promising in-situ chemical oxidation (ISCO) technologies for remediation of soil and groundwater contaminated by antibiotics. The present study reported that thermally activated persulfate oxidation of sulfonamides (SAs) bearing six-membered heterocyclic rings, e.g., sulfamethazine (SMZ), sulfapyridine (SPD), sulfadiazine (SDZ), sulfadimethoxine (SDM), and sulfachloropyridazine (SCP), all produced SO2 extrusion products (SEPs), a phenomenon that is of potential importance, but not systematically studied. As an electrophilic oxidant, SO4•- tends to attack the aniline moiety, the reactive site of SAs, via electro-transfer mechanism. The resulting anilinyl radical cations are subjected to further intermolecular Smiles-type rearrangement to produce SEPs. Formation of SEPs is expected to occur in other SR-AOPs as well. The temperature-dependent evolution pattern of SEP of SMZ, 4-(2-imino-4,6-dimethylpyrimidin-1(2H)-yl)aniline, can be well fitted by kinetic modeling concerning sequential formation and transformation of intermediate product. The presence of natural organic matter (NOM) influenced the evolution patterns of 4-(2-imino-4,6-dimethylpyrimidin-1(2H)-yl)aniline significantly. Toxicological effects of SEPs on ecosystem and human health remain largely unknown, thus, further monitoring studies are highly desirable.
-
sulfate radical based oxidation of antibiotics sulfamethazine sulfapyridine sulfadiazine sulfadimethoxine and sulfachloropyridazine formation of so 2 extrusion products and effects of natural organic matter
Science of The Total Environment, 2017Co-Authors: Yuanyuan Shi, Lu Wang, Corinne Ferronato, Jeanmarc ChovelonAbstract:The widespread occurrence of sulfonamide antibiotics in the environment has raised great concerns about their potential to proliferate antibacterial resistance. Sulfate radical (SO4•-) based advanced oxidation processes (SR-AOPs) are promising in-situ chemical oxidation (ISCO) technologies for remediation of soil and groundwater contaminated by antibiotics. The present study reported that thermally activated persulfate oxidation of sulfonamides (SAs) bearing six-membered heterocyclic rings, e.g., sulfamethazine (SMZ), sulfapyridine (SPD), sulfadiazine (SDZ), sulfadimethoxine (SDM), and sulfachloropyridazine (SCP), all produced SO2 extrusion products (SEPs), a phenomenon that is of potential importance, but not systematically studied. As an electrophilic oxidant, SO4•- tends to attack the aniline moiety, the reactive site of SAs, via electro-transfer mechanism. The resulting anilinyl radical cations are subjected to further intermolecular Smiles-type rearrangement to produce SEPs. Formation of SEPs is expected to occur in other SR-AOPs as well. The temperature-dependent evolution pattern of SEP of SMZ, 4-(2-imino-4,6-dimethylpyrimidin-1(2H)-yl)aniline, can be well fitted by kinetic modeling concerning sequential formation and transformation of intermediate product. The presence of natural organic matter (NOM) influenced the evolution patterns of 4-(2-imino-4,6-dimethylpyrimidin-1(2H)-yl)aniline significantly. Toxicological effects of SEPs on ecosystem and human health remain largely unknown, thus, further monitoring studies are highly desirable.
