Sulfamethoxazole Transformation by Heat-Activated Persulfate: Linking Transformation Products Patterns with Carbon and Nitrogen Isotope Fractionation

Environmental Science & Technology, Journal Year: 2025, Volume and Issue: unknown

Published: March 10, 2025

Sulfamethoxazole (SMX) is a frequently detected antibiotic in groundwater, raising environmental concerns. Persulfate oxidation used for micropollutant removal. To investigate SMX transformation by persulfate, experiments were conducted using heat-activated persulfate at pH 3, 7, and 10. TP269a (SMX-hydroxylamine) TP178 identified as the dominant TPs across levels. The exclusive formation of 4-nitroso-SMX, 4-nitro-SMX, TP518 3 highlighted role SO4•- attacking NH2. At 7 10, 3A5MI emerged TP. Carbon isotopic fractionation (εC = -1.3 ± 0.5‰, -1.1 0.4‰, 0.3‰ 10) remained consistent levels, caused involving C-S bond cleavage. An inverse nitrogen isotope (εN +0.68 0.11‰) was associated with SO4•--induced single-electron transfer. Conversely, normal 10 -0.27 0.04‰) N-H cleavage H abstraction through HO• N-S indicated that pathway involved reactions, accounting 74%. Overall, results highlight potential CSIA to elucidate pathways.

Language: Английский

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Novel extraction methods and compound-specific isotope analysis of methoxychlor in environmental water and aquifer slurry samples

The Science of The Total Environment, Journal Year: 2024, Volume and Issue: 931, P. 172858 - 172858

Published: May 5, 2024

Multi-element compound-specific stable isotope analysis (ME-CSIA) allows monitoring the environmental behavior and transformation of most common persistent contaminants. Recent advancements in analytical techniques have extended applicability ME-CSIA to organic micropollutants, including pesticides. Nevertheless, application this methodology remains unexplored concerning harmful insecticides such as methoxychlor, a polar organochlorine pesticide usually detected soil groundwater. This study introduces methods for dual carbon chlorine (δ

Language: Английский

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Direct Phototransformation of Sulfamethoxazole Characterized by Four-Dimensional Element Compound Specific Isotope Analysis

Environmental Science & Technology, Journal Year: 2024, Volume and Issue: 58(23), P. 10322 - 10333

Published: June 1, 2024

The antibiotic sulfamethoxazole (SMX) undergoes direct phototransformation by sunlight, constituting a notable dissipation process in the environment. SMX exists both neutral and anionic forms, depending on pH conditions. To discern photodegradation of at various levels differentiate it from other transformation processes, we conducted under simulated sunlight 7 3, employing product (TP) compound-specific stable isotope analyses. At 7, primary TPs were sulfanilic acid 3A5MI, followed sulfanilamide (5-methylisoxazol-3-yl)-sulfamate, whereas photoisomer was dominant product, 3A5MI. Isotope fractionation patterns revealed normal 13C, 34S, inverse 15N fractionation, which exhibited significant differences between 3. This indicates pH-dependent phototransformation. hydrogen isotopic composition remained during levels. Moreover, there no variation observed 33S two levels, indicating that mass-independent remains unaffected changes pH. analysis main single-element suggests varying combinations bond cleavages different values, resulting distinct fractionation. Conversely, dual-element values did not significantly differ, cleavage several bonds parallel. Hence, prudent interpretation these systems is warranted. These findings highlight potential multielement characterizing SMX, thereby facilitating evaluation its natural attenuation through photolysis

Language: Английский

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Carbon and Nitrogen Isotope Fractionations During Biotic and Abiotic Transformations of 2,4-Dinitroanisole (DNAN)

Environmental Science & Technology, Journal Year: 2024, Volume and Issue: 58(13), P. 5996 - 6006

Published: March 20, 2024

2,4-Dinitroanisole (DNAN) is a main constituent in various new insensitive munition formulations. Although DNAN susceptible to biotic and abiotic transformations, many environmental instances, transformation mechanisms are difficult resolve, distinguish, or apportion on the basis solely of analysis concentrations. We used compound-specific isotope (CSIA) investigate characteristic fractionations (by three microbial consortia pure cultures) 9,10-anthrahydroquinone-2-sulfonic acid [AHQS]) transformations DNAN. The correlations enrichment factors (ΛN/C) for had range values from 4.93 ± 0.53 12.19 1.23, which entirely distinct ΛN/C reported previously alkaline hydrolysis, enzymatic reduction by Fe2+-bearing minerals iron-oxide-bound Fe2+, UV-driven phototransformations. value associated with AHQS was 38.76 2.23, within albeit mean lower. These results enhance database effects accompanying under environmentally relevant conditions, allowing better evaluation extents that occur soils, groundwaters, surface waters, marine environment.

Language: Английский

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Processing of natural fibre and method improvement for removal of endocrine-disrupting compounds

Chemosphere, Journal Year: 2021, Volume and Issue: 291, P. 132726 - 132726

Published: Oct. 27, 2021

Language: Английский

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Occurrence of Banned and Currently Used Herbicides, in Groundwater of Northern Greece: A Human Health Risk Assessment Approach

International Journal of Environmental Research and Public Health, Journal Year: 2022, Volume and Issue: 19(14), P. 8877 - 8877

Published: July 21, 2022

The presence of pesticide residues in groundwater, many years after their phase out European Union verifies that the persistence aquifer is much higher than other environmental compartments. Currently used and banned pesticides were monitored Northern Greece aquifers a human health risk assessment was conducted. target compounds herbicides metolachlor (MET), terbuthylazine (TER), atrazine (ATR) its metabolites deisopropylatrazine (DIA), deethylatrazine (DEA) hydroxyatrazine (HA). Eleven sampling sites selected to have representatives different types wells. Pesticides extracted by solid-phase extraction analyzed liquid chromatography. MET detected 100% water samples followed ATR (96.4%), DEA HA (88.6%), DIA (78.2%) TER (67.5%). ATR, DIA, DEA, HA, mean concentrations 0.18, 0.29, 0.14, 0.09, 0.16 0.15 μg/L, respectively. Obtained results compared with historical data from previous monitoring studies temporal trends assessed. Preferential flow major factor facilitating leaching within month herbicide application. Moreover, apparent age groundwater reduced dissipation rates on resulted long-term detection legacy pesticides. Although had been more 18 ago, it frequently some cases over maximum permissible limit. Furthermore, calculated for two groups though drinking consumption. In all examined wells, sum HQ values lower unity. As result, wells are considered safe according acute process. However, causes concerns related chronic toxicity, since R greater parametric one 1 × 10−6 advised USEPA, both groups.

Language: Английский

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Contaminant Removal from Wastewater by Microalgal Photobioreactors and Modeling by Artificial Neural Network

Water, Journal Year: 2022, Volume and Issue: 14(24), P. 4046 - 4046

Published: Dec. 12, 2022

The potential of microalgal photobioreactors in removing total ammonia nitrogen (TAN), chemical oxygen demand (COD), caffeine (CAF), and N,N-diethyl-m-toluamide (DEET) from synthetic wastewater was studied. Chlorella vulgaris achieved maximum removal 62.2% TAN, 52.8% COD, 62.7% CAF, 51.8% DEET. By mixing C. with activated sludge, the photobioreactor showed better performance, 82.3% 67.7% 85.7% 73.3% Proteobacteria, Bacteroidetes, Chloroflexi were identified as dominant phyla sludge. processes then optimized by artificial neural network (ANN). High R2 values (>0.99) low mean squared errors demonstrated that ANN could optimize reactors’ performance. toxicity testing high concentrations contaminants (>10 mg/L) long contact time (>48 h) reduced chlorophyll protein contents microalgae. Overall, a green technology for treatment using microalgae bacteria consortium has its potentials sustainable management water resources.

Language: Английский

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Indirect photodegradation of ofloxacin in simulated seawater: Important roles of DOM and environmental factors

Frontiers in Marine Science, Journal Year: 2023, Volume and Issue: 10

Published: March 1, 2023

Dissolved organic matter (DOM) plays a non-negligible role in the indirect photodegradation of contaminants. This research investigated roles DOM and environmental factors (salinity, pH, NO 3 − , HCO ) ofloxacin (OFX) simulated seawater. Results showed that can significantly accelerate OFX, 1 O 2 * were main reactive intermediates (RIs) could promote OFX. Fluorescence excitation–emission matrix spectroscopy–parallel factor analysis (EEMs-PARAFAC) was used to divide into four fluorescence components. The rate OFX affected by structure, terrigenous usually produced more RIs Increased salinity promotes while increased concentration had no effect on photodegradation. pH formation structure thereby affecting solution, which is due carbonate radical (CO ). study essential understanding providing novel insight fate, removal, transformation

Language: Английский

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Combined effects of micropollutants and their degradation on prokaryotic communities at the sediment–water interface

Scientific Reports, Journal Year: 2024, Volume and Issue: 14(1)

Published: July 22, 2024

Pesticides and pharmaceuticals enter aquatic ecosystems as complex mixtures. Various processes govern their dissipation effect on the sediment surface waters. These micropollutants often show persistence can adversely affect microorganisms even at low concentrations. We investigated effects procaryotic communities of metformin (antidiabetic drug), metolachlor (agricultural herbicide), terbutryn (herbicide in building materials). contaminants were introduced individually or a mixture (17.6 µM per micropollutant) into laboratory microcosms mimicking sediment-water interface. Metformin completely dissipated within 70 days, whereas persisted. Dissipation did not differ whether part mixture. Sequence analysis 16S rRNA gene amplicons evidenced distinct responses prokaryotic both water. Prokaryotic community variations mainly driven by matrix composition incubation time. Micropollutant exposure played secondary but influential role, with pronounced recalcitrant micropollutant Antagonistic synergistic non-additive identified for specific taxa across taxonomic levels response to This study underscores importance considering diversity interactions between micropollutants, communities, respective environments when examining interfaces affected multiple contaminants.

Language: Английский

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Dissipation Kinetics, Leaching, and Ecological Risk Assessment of S-Metolachlor and Benfluralin Residues in Soil

Environments, Journal Year: 2024, Volume and Issue: 11(1), P. 18 - 18

Published: Jan. 18, 2024

The use of selective herbicides is one the best methods for weed management. However, extensive can have adverse impacts on non-target organisms. goals this study were to assess dissipation kinetics, leaching, and ecological risk assessment S-metolachlor benfluralin residues in silty loam soil planted with chickpea (Cicer arietinum L.). experimental setup included four different layers replications corresponding an randomized complete block design consisting 16 plots. application doses 1350 1920 g a.i./ha, respectively, according manufacturer recommendations. Soil samples split into depths, 0 20 cm (Layer A), 40 B), 60 C), 80 D), determine kinetics leaching behavior herbicides. Gas chromatography coupled electron capture detector (GC-ECD) method was developed validated determination soil. analytes extracted from distilled water ethyl acetate followed by solid-phase extraction (SPE). limit quantification (LOQ) 0.1 μg/g, recoveries ranges 81% 97% 88% 101%, relative standard deviations (RSD) less than 9.7%. (0–20 cm) first-order half-lives 21.66 30.13 days, respectively. results obtained 20–80 profile showed that both presented high following preferential flow. Also, a conducted top 0–20 profile, estimating toxicity–exposure ratio (TER) organisms quotient (RQ). mean herbicide levels found at studied days (2 h) experiment used assessment. In first case, pesticide concentration (MPC) gives worst-case scenario (ws); second (ds) given using respective MPC. all cases, TER RQ values corresponds higher

Language: Английский

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