Monitoring dissolved organic matter in wastewater and drinking water treatments using spectroscopic analysis and ultra-high resolution mass spectrometry

Water Research, Год журнала: 2020, Номер 188, С. 116406 - 116406

Опубликована: Сен. 9, 2020

Язык: Английский

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Singlet Oxygen Quantum Yields in Environmental Waters

Chemical Reviews, Год журнала: 2021, Номер 121(7), С. 4100 - 4146

Опубликована: Март 8, 2021

Singlet oxygen (1O2) is a reactive species produced in sunlit waters via energy transfer from the triplet states of natural sensitizers. There has been an increasing interest measuring apparent 1O2 quantum yields (ΦΔ) aquatic and atmospheric organic matter samples, driven part by fact that this parameter can be used for environmental fate modeling contaminants to advance our understanding dissolved photophysics. However, lack reproducibility across research groups publications remains challenge significantly limits usability literature data. In first review, we critically evaluate experimental techniques have determine ΦΔ values matter, identify quantify sources errors potentially explain large variability literature, provide general recommendations future studies. second part, qualitative overview known trends as function type, isolation extraction procedures, bulk water chemistry parameters, molecular spectroscopic features, chemical treatments, wavelength, season, location. This review supplemented with comprehensive database samples.

Язык: Английский

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Visible-light-assisted peroxymonosulfate activation by metal-free bifunctional oxygen-doped graphitic carbon nitride for enhanced degradation of imidacloprid: Role of non-photochemical and photocatalytic activation pathway

Journal of Hazardous Materials, Год журнала: 2021, Номер 423, С. 127048 - 127048

Опубликована: Авг. 29, 2021

Язык: Английский

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Comparing Photoactivities of Dissolved Organic Matter Released from Rice Straw-Pyrolyzed Biochar and Composted Rice Straw

Environmental Science & Technology, Год журнала: 2022, Номер 56(4), С. 2803 - 2815

Опубликована: Янв. 28, 2022

Here, we systematically compared the photoactivity and photobleaching behavior between dissolved black carbon (DBC) from rice straw biochar leached organic (LDOC) compost using complementary techniques. The Fourier transform-ion cyclotron resonance mass spectrometry (FT-ICR MS) analysis showed that DBC was dominated by polycyclic aromatic (55.1%) tannin-like molecules (24.1%), while LDOC lignin-like (58.9%) (19.7%). Under simulated sunlight conditions, had much higher apparent quantum yields for 3DOM* 1O2 but lower •OH than LDOC. After a 168 h irradiation, total number of formulas identified FT-ICR MS decreased 40.1% with concurrent increases in O/C H/C ratios also decreases double bond equivalence minus oxygen (DBE – O) average molecular weight gel permeation chromatography. However, despite large UVA254 DOC, only 12.0% nearly unchanged ratio, DBE O values, distribution, benzenepolycarboxylic condensation (BACon) index regardless percentage condensed (ConAC %). Compared LDOC, photolysis less oxidative destructive mainly via breakup small portion highly rings, probably accompanied photodecarboxylation.

Язык: Английский

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Dissolved Organic Matter Photoreactivity Is Determined by Its Optical Properties, Redox Activity, and Molecular Composition

Environmental Science & Technology, Год журнала: 2023, Номер 57(16), С. 6703 - 6711

Опубликована: Апрель 11, 2023

Predicting the formation of photochemically produced reactive intermediates (PPRI) during irradiation dissolved organic matter (DOM) has remained challenging given complex nature this material and differences in PPRI mechanisms. We investigate role DOM composition photoreactivity using 48 samples that span range freshwater systems wastewater. relate quantum yields for excited triplet-state (fTMP), singlet oxygen (Φ1O2), hydroxylating species (Φ•OH) to determined spectroscopy, Fourier-transform ion cyclotron resonance mass spectrometry, electron-donating capacity (EDC). fTMP Φ1O2 follow similar trends are correlated with bulk properties derived from UV–vis spectra EDC. In contrast, no individual property can be used predict Φ•OH. At molecular level, subset is positively both Φ•OH EDC distinct formulas related Φ1O2, demonstrating •OH 1O2 formed different fractions. Multiple linear regressions each parameters multiple techniques, complementary methods ideal characterizing because technique only a DOM.

Язык: Английский

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Spatiotemporal response of dissolved organic matter diversity to natural and anthropogenic forces along the whole mainstream of the Yangtze River

Water Research, Год журнала: 2023, Номер 234, С. 119812 - 119812

Опубликована: Март 1, 2023

Язык: Английский

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Prediction of Photochemical Properties of Dissolved Organic Matter Using Machine Learning

Environmental Science & Technology, Год журнала: 2023, Номер 57(46), С. 17971 - 17980

Опубликована: Апрель 8, 2023

Apparent quantum yields (Φ) of photochemically produced reactive intermediates (PPRIs) formed by dissolved organic matter (DOM) are vital to element cycles and contaminant fates in surface water. Simultaneous determination ΦPPRI values from numerous water samples through existing experimental methods is time consuming ineffective. Herein, machine learning models were developed with a systematic data set including 1329 points predict the three ΦPPRIs (Φ3DOM*, Φ1O2, Φ·OH) based on DOM spectral parameters, conditions, calculation parameters. The best predictive performances for Φ3DOM*, Φ·OH achieved using CatBoost model, which outperformed traditional linear regression models. significances wavelength range parameters predictions revealed, suggesting that lower molecular weight, aromatic content, more autochthonous portion possessed higher ΦPPRIs. Chain constructed adding predicted Φ3DOM* as new feature into Φ1O2 models, consequently improved performance but worsened prediction likely due complex formation pathways ·OH. Overall, this study offered robust across interlaboratory differences provided insights relationship between PPRIs properties.

Язык: Английский

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Molecular-Level Transformation of Dissolved Organic Matter during Oxidation by Ozone and Hydroxyl Radical

Environmental Science & Technology, Год журнала: 2020, Номер 54(16), С. 10351 - 10360

Опубликована: Июль 22, 2020

Ozonation of drinking and wastewater relies on ozone (O3) hydroxyl radical (•OH) as oxidants. Both oxidants react with dissolved organic matter (DOM) alter its composition, but the selectivity two mechanisms reactivity DOM moieties are largely unknown. The reactions O3 •OH isolates were studied by varying specific doses (0.1–1.3 mg-O3/mg-C) at pH 7. Additionally, conditions that favor (i.e., addition an scavenger) or 11) investigated. decreases aromaticity, apparent molecular weight, electron donating capacity (EDC) large changes observed when is main oxidant (e.g., EDC 63–77% for 1.3 mg-O3/mg-C). highly aromatic, reduced formulas detected using high-resolution mass spectrometry (O:C = 0.48 ± 0.12; H:C 1.06 0.23), while also oxidizes more saturated (H:C 1.64 0.26). Established between model compounds one to oxygen atoms) atom decarboxylation) produce oxidized > 1.0). This study provides molecular-level evidence within DOM.

Язык: Английский

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Kinetic Consideration of Photochemical Formation and Decay of Superoxide Radical in Dissolved Organic Matter Solutions

Environmental Science & Technology, Год журнала: 2020, Номер 54(6), С. 3199 - 3208

Опубликована: Фев. 19, 2020

The photochemical formation and decay rates of superoxide radical ions (O2•–) in irradiated dissolved organic matter (DOM) solutions were directly determined by the chemiluminescent method. Under irradiation, uncatalyzed catalyzed O2•– dismutation account for ∼25% total degradation air-saturated DOM solutions. Light-induced loss, which does not produce H2O2, was observed. Both light-induced loss are positively correlated with electron-donating capacities DOM, suggesting that phenolic moieties play a dual role behavior O2•–. In conditions, quantum yields 12 varied narrow range, from 1.8 to 3.3‰, average (2.4 ± 0.5)‰. yield nonlinearly increased increasing oxygen concentration. Therefore, one-electron reducing intermediates, precursor O2•–, calculated as (5.0 0.4)‰. High-energy triplets (3DOM*, ET > 200 kJ mol–1) 1O2 quenching experiments indicate 3DOM* minor roles production. These results useful predicting sunlit surface waters.

Язык: Английский

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Role of Reactive Halogen Species in Disinfection Byproduct Formation during Chlorine Photolysis

Environmental Science & Technology, Год журнала: 2020, Номер 54(15), С. 9629 - 9639

Опубликована: Июнь 29, 2020

The multiple reactive oxidants produced during chlorine photolysis effectively degrade organic contaminants water treatment, but their role in disinfection byproduct (DBP) formation is unclear. impact of on dissolved matter (DOM) composition and DBP investigated using lake collected after coagulation, flocculation, filtration at pH 6.5 8.5 with irradiation three wavelengths (254, 311, 365 nm). steady-state concentrations hydroxyl radical decrease by 38–100% drinking compared to ultrapure water, which primarily attributed scavenging natural constituents. Chlorine transforms DOM through mechanisms produce that more aliphatic nature contains novel high molecular weight chlorinated DBPs are detected via high-resolution mass spectrometry. Quenching experiments demonstrate species partially responsible for the halogenated DOM, haloacetic acids, haloacetonitriles, whereas trihalomethane decreases photolysis. Furthermore, transformation due direct alters such it chlorine, also contributes enhanced

Язык: Английский

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