Particulate nitrate photolysis in the atmosphere

Environmental Science Atmospheres, Journal Year: 2022, Volume and Issue: 2(2), P. 111 - 127

Published: Jan. 1, 2022

Particulate nitrate photolysis can lead to the formation of secondary inorganic and organic aerosols that affect climate, air quality, human health.

Language: Английский

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Fluidic MXene Electrode Functionalized with Iron Single Atoms for Selective Electrocatalytic Nitrate Transformation to Ammonia

Environmental Science & Technology, Journal Year: 2023, Volume and Issue: 57(28), P. 10458 - 10466

Published: June 30, 2023

The growth of renewable energy industries and the ongoing need for fertilizer in agriculture have created a sustainable production ammonia (NH3) using low-cost, environment-friendly techniques. electrocatalytic nitrate (NO3–) reduction reaction (NO3RR) has potential to improve both management environmental nitrogen recycling synthetic nutrients. However, NO3RR is frequently hindered by incomplete NO3– conversion, sluggish kinetics, suppression hydrogen evolution (HER). Inspired specific local electronic structures that are adjustable single-atom catalysts, this work presents nanohybrid filter with iron single atoms (FeSA) immobilized on MXene. fabricated FeSA/MXene exhibited maximum NH3 Faradaic efficiency selectivity (82.9 99.2%, respectively) were higher than those filters made Fe nanoparticles anchored MXene (FeNP/MXene) (69.2 81.3%, alone (32.8 52.4%, respectively), measured at an initial pH 7 applied −1.4 V vs Ag/AgCl. Density functional theory calculations revealed that, compared FeNP/MXene filter, prevented competition from HER reduced activation potential-limiting step (*NO *NHO) synthesis thermodynamically favorable . This highlights alternative strategy achieving synergistic removal nutrient recovery durable catalytic activity stability.

Language: Английский

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Unveiling the underestimated direct emissions of nitrous acid (HONO)

Proceedings of the National Academy of Sciences, Journal Year: 2023, Volume and Issue: 120(35)

Published: Aug. 21, 2023

Gaseous nitrous acid (HONO) is a critical source of hydroxyl radicals (OH) in the troposphere. While both direct and secondary sources contribute to atmospheric HONO, emissions have traditionally been considered minor contributors. In this study, we developed δ 15 N 18 O isotopic fingerprints identify six HONO emission conducted 1-y case study on composition at rural urban sites. Interestingly, identified that livestock farming previously overlooked determined its ammonia (NH 3 ) ratio. Additionally, our results revealed spatial temporal variations can be partially attributed emissions. Through detailed budget analysis incorporating agricultural sources, found accounted for 39~45% production areas across different seasons. The findings were further confirmed by chemistry transport model simulations, highlighting significance their impact air quality North China Plain. These provide compelling evidence play more substantial role contributing than believed. Moreover, may serve as valuable tool research reactive nitrogen gases.

Language: Английский

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Recent Progress in Atmospheric Chemistry Research in China: Establishing a Theoretical Framework for the “Air Pollution Complex”

Advances in Atmospheric Sciences, Journal Year: 2023, Volume and Issue: 40(8), P. 1339 - 1361

Published: April 28, 2023

Atmospheric chemistry research has been growing rapidly in China the last 25 years since concept of "air pollution complex" was first proposed by Professor Xiaoyan TANG 1997. For papers published 2021 on air (only included Web Science Core Collection database were considered), more than 24 000 authored or co-authored scientists working China. In this paper, we review a limited number representative and significant studies atmospheric few years, including (1) sources emission inventories, (2) chemical processes, (3) interactions with meteorology, weather climate, (4) between biosphere atmosphere, (5) data assimilation. The intention not to provide complete all progress made but rather serve as starting point for learning about advances reviewed paper have enabled theoretical framework complex be established, provided robust scientific support highly successful control policies China, created great opportunities education, training, career development many graduate students young scientists. This further highlights that developing low-income countries are heavily affected can benefit from these advances, whilst at same time acknowledging challenges still remain hopefully addressed over next decades.

Language: Английский

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Sensitive Detection of Nitrite and Nitrate in Seawater by 222 nm UV-Irradiated Photochemical Conversion to Peroxynitrite and Ion Chromatography-Luminol Chemiluminescence System

Environmental Science & Technology, Journal Year: 2023, Volume and Issue: 57(14), P. 5924 - 5933

Published: March 27, 2023

Sensitive detection methods for nitrite (NO2–) and nitrate (NO3–) ions are essential to understand the nitrogen cycle environmental protection public health. Herein, we report a method that combines ion-chromatographic separation of NO2– NO3–, on-line photochemical conversion these peroxynitrite (ONOO–) by irradiation with 222 nm excimer lamp, chemiluminescence from reaction between luminol ONOO–. The limits NO3– were 0.01 0.03 μM, respectively, linear ranges 0.010–2.0 0.10–3.0 at an injection volume 1 μL. results obtained proposed seawater analysis corresponded those reference (AutoAnalyzer based on Griess reaction). As can measure ONOO– picomolar concentrations, our is expected be able detect concentrations owing high ratio (>60%), assuming contamination background issues resolved. This has potential emerge as innovative technology in various samples.

Language: Английский

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Comparison of aqueous secondary organic aerosol (aqSOA) product distributions from guaiacol oxidation by non-phenolic and phenolic methoxybenzaldehydes as photosensitizers in the absence and presence of ammonium nitrate

Atmospheric chemistry and physics, Journal Year: 2023, Volume and Issue: 23(4), P. 2859 - 2875

Published: March 2, 2023

Abstract. Aromatic carbonyls (e.g., methoxybenzaldehydes), an important class of photosensitizers, are abundant in the atmosphere. Photosensitization and nitrate-mediated photo-oxidation can occur simultaneously, yet studies about their interactions, particularly for aqueous secondary organic aerosol (aqSOA) formation, remain limited. This study compared non-phenolic (3,4-dimethoxybenzaldehyde, DMB) phenolic (vanillin, VL) methoxybenzaldehydes as photosensitizers aqSOA formation via guaiacol (GUA) oxidation absence presence ammonium nitrate (AN) under atmospherically relevant cloud fog conditions. GUA by triplet excited states DMB (3DMB∗) (GUA + was ∼ 4 times faster exhibited greater light absorption than 3VL∗ VL). Both VL formed composed oligomers, functionalized monomers, oxygenated ring-opening species, N-containing products AN. The observation N-heterocycles such imidazoles indicates participation reactions. majority generated comprises potential brown carbon (BrC) chromophores. Oligomerization functionalization dominated VL, but appeared to be more due contributions from itself. AN did not significantly affect kinetics, it had distinct effects on product distributions, likely differences photosensitizing abilities structural features VL. In particular, extensive fragmentation AN, increased oligomers may VL-derived phenoxy radicals induced ⚫OH or ⚫NO2 photolysis. Furthermore, nitrated observed both alone imply that photosensitized reactions promote nitration. work demonstrates how non-carbonyl phenol oxidation. Potential interactions between photosensitization photolysis were also elucidated. These findings facilitate a better understanding highlight importance these

Language: Английский

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Photocatalytic O2 activation carried out by organic aerosol: A case study of 1, 8-naphthalic anhydride

Applied Catalysis B Environment and Energy, Journal Year: 2024, Volume and Issue: 349, P. 123889 - 123889

Published: April 24, 2024

Language: Английский

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Phase State Regulates Photochemical HONO Production from NaNO₃/Dicarboxylic Acid Mixtures

Environmental Science & Technology, Journal Year: 2024, Volume and Issue: 58(17), P. 7516 - 7528

Published: April 17, 2024

Field observations of daytime HONO source strengths have not been well explained by laboratory measurements and model predictions up until now. More efforts are urgently needed to fill the knowledge gaps concerning how environmental factors, especially relative humidity (RH), affect particulate nitrate photolysis. In this work, two critical attributes for atmospheric particles, i.e., phase state bulk-phase acidity, both influenced ambient RH, were focused illuminate key regulators reactive nitrogen production from typical internally mixed systems, NaNO3 dicarboxylic acid (DCA) mixtures. The dissolution only few oxalic (OA) crystals resulted in a remarkable 50-fold increase compared pure photolysis at 85% RH. Furthermore, rates (PHONO) increased about 1 order magnitude as RH rose <5% 95%, initially exhibiting an almost linear dependence on amount surface absorbed water subsequently showing substantial PHONO once deliquescence occurred approximately 75% NaNO3/malonic (MA) NaNO3/succinic (SA) mixtures exhibited similar effects photochemical production. These results offer new perspective aerosol physicochemical properties influence atmosphere.

Language: Английский

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Decay Kinetics and Absorption Changes of Methoxyphenols and Nitrophenols during Nitrate-Mediated Aqueous Photochemical Oxidation at 254 and 313 nm

ACS Earth and Space Chemistry, Journal Year: 2022, Volume and Issue: 6(4), P. 1115 - 1125

Published: March 28, 2022

Brown carbon (BrC) absorbs radiation in the near-UV and visible ranges, affecting atmospheric photochemistry radiative forcing. Our understanding on photochemical transformation of BrC is still limited, especially when mixed with abundant photochemically labile inorganic salt, nitrate. Herein, we investigate reactions four chromophores, including two methoxyphenols nitrophenols. Experiments were conducted absence presence different concentrations H2O2 nitrate lights 254 313 nm. The results show that pseudo-first-order decay rate constants (k) these compounds at nm illumination approximately 10 times lower than those nm, demonstrating longer lifetimes chromophores under tropospherically relevant irradiation. Photo-enhancement range was observed most experiments, lasting longer, indicating prolonged effects nascent transformed Methoxyphenols had higher averaged k values nitrophenols during direct photolysis or lights, but for high-nitrate (or high-H2O2) conditions approached methoxyphenols. photo-enhancement substantially contributed by nitro products, while mainly hydroxylated and/or dimerized products. reveal similarity difference between nitrophenols, which may help better understand aging types model representation their

Language: Английский

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Aqueous-phase chemistry of atmospheric phenolic compounds: A critical review of laboratory studies

The Science of The Total Environment, Journal Year: 2022, Volume and Issue: 856, P. 158895 - 158895

Published: Sept. 18, 2022

Language: Английский

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