Emission Rates of Volatile Organic Compounds from Humans

Environmental Science & Technology, Год журнала: 2022, Номер 56(8), С. 4838 - 4848

Опубликована: Апрель 7, 2022

Human-emitted volatile organic compounds (VOCs) are mainly from breath and the skin. In this study, we continuously measured VOCs in a stainless-steel environmentally controlled climate chamber (22.5 m3, air change rate at 3.2 h–1) occupied by four seated human volunteers using proton transfer reaction time-of-flight mass spectrometry gas chromatography spectrometry. Experiments with whole body, breath-only, dermal-only emissions were performed under ozone-free ozone-present conditions. addition, effect of temperature, relative humidity, clothing type, age was investigated for whole-body emissions. Without ozone, total emission (ER) 2180 ± 620 μg h–1 per person (p–1), dominated exhaled chemicals. The ERs oxygenated positively correlated enthalpy air. Under conditions (∼37 ppb), ER doubled, increase driven resulting skin surface lipids/ozone reactions, which increased humidity. Long (more covered skin) found to reduce but enhanced certain chemicals related clothing. derived study provide valuable data set various can be used models better predict indoor quality, especially highly environments.

Язык: Английский

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Residential air‐change rates: A critical review

Indoor Air, Год журнала: 2021, Номер 31(2), С. 282 - 313

Опубликована: Янв. 5, 2021

Air-change rate is an important parameter influencing residential air quality. This article critically assesses the state of knowledge regarding air-change rates, emphasizing periods normal occupancy. Cumulatively, about 40 prior studies have measured rates in approximately 10,000 homes using tracer gases, including metabolic CO2. The central tendency determined these reasonably described as lognormal with a geometric mean 0.5 h−1 and standard deviation 2.0. However, means individual vary, mainly within range 0.2–1 h−1. also vary time residences. Factors include weather (indoor–outdoor temperature difference wind speed), leakiness building envelope, and, when present, operation mechanical ventilation systems. Occupancy-associated factors are important, window opening, induced exhaust from flued combustion, use heating cooling Empirical methodological challenges remain to be effectively addressed. These clarifying variation residences during occupancy understanding influence time-varying on tracer-gas measurement techniques. Important opportunities available improve interzonal flows affecting source-to-exposure relationships for indoor pollutants.

Язык: Английский

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Recent Advances on Photocatalytic and Electrochemical Oxidation for Ammonia Treatment from Water/Wastewater

ACS ES&T Engineering, Год журнала: 2020, Номер 1(3), С. 310 - 325

Опубликована: Дек. 7, 2020

Heterogeneous photocatalytic (PC) and electrochemical (EC) oxidation of ammonia/ammonium pollutants in water/wastewater have been thoroughly investigated for ammonia abatement from aqueous streams, as there are continuing needs developing alternative on-site easily controllable treatment approaches contrast to conventional methods. Depending on the contamination level, water matrix characters, regulatory consideration, PC EC wastewater or integration with other processes exhibit their own advantages disadvantages at specific conditions. The primarily relies situ generated strong oxidants such hydroxyl radicals holes, but reactivities relatively slower environmentally relevant pH In contrast, indirect based active chlorine species is more efficient exhibits some compared chemical chlorination approach. Although we gained much scientific knowledge this research topic recent years, so far has not yet lead broad industry adoption due many concerns about technical drawbacks economic feasibilities; hence, it necessary reexamine efforts made field. Upon survey literature, aim review summarize discuss achievements key issues driven order avoid redundant studies that concentrate well-established point out directions move these techniques forward future.

Язык: Английский

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Indoor acids and bases

Indoor Air, Год журнала: 2020, Номер 30(4), С. 559 - 644

Опубликована: Март 31, 2020

Numerous acids and bases influence indoor air quality. The most abundant of these species are CO2 (acidic) NH3 (basic), both emitted by building occupants. Other prominent inorganic HNO3, HONO, SO2, H2SO4, HCl, HOCl. Prominent organic include formic, acetic, lactic; nicotine is a noteworthy base. Sources N-, S-, Cl-containing can ventilation from outdoors, combustion, consumer product use, chemical reactions. Organic commonly more indoors than with sources including occupants, wood, cooking. Beyond nicotine, other amines. Acids partition among the gas-phase, airborne particles, bulk water, surfaces; relevant thermodynamic parameters governing partitioning acid-dissociation constant (Ka), Henry's law (KH), octanol-air coefficient (Koa). Condensed-phase water strongly influences fate also medium for interactions. Indoor surfaces be large reservoirs bases. This extensive review state knowledge establishes foundation future inquiry to better understand how suitability environments cultural artifacts, sensitive equipment.

Язык: Английский

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How Do Indoor Environments Affect Air Pollution Exposure?

Environmental Science & Technology, Год журнала: 2020, Номер 55(1), С. 100 - 108

Опубликована: Дек. 7, 2020

ADVERTISEMENT RETURN TO ISSUEPREVPerspectiveNEXTHow Do Indoor Environments Affect Air Pollution Exposure?Allen H. Goldstein*Allen GoldsteinDepartment of Environmental Science, Policy, and Management University California, Berkeley, California 94720, United StatesDepartment Civil Engineering, States*E-mail: [email protected]More by Allen GoldsteinView Biographyhttp://orcid.org/0000-0003-4014-4896, William W NazaroffWilliam NazaroffDepartment StatesMore Nazaroffhttp://orcid.org/0000-0001-5645-3357, Charles J. WeschlerCharles WeschlerInternational Centre for Environment Energy, Department Technical Denmark, Lyngby 2800, DenmarkEnvironmental Occupational Health Sciences Institute, Rutgers University, Piscataway, New Jersey 08854, Weschlerhttp://orcid.org/0000-0002-9097-5850, Jonathan WilliamsJonathan WilliamsMax Planck Institute Chemistry, 55128 Mainz, GermanyMore Williamshttp://orcid.org/0000-0001-9421-1703Cite this: Environ. Sci. Technol. 2021, 55, 1, 100–108Publication Date (Web):December 7, 2020Publication History Received26 August 2020Published online7 December inissue 5 January 2021https://pubs.acs.org/doi/10.1021/acs.est.0c05727https://doi.org/10.1021/acs.est.0c05727review-articleACS PublicationsCopyright © 2020 American Chemical SocietyRequest reuse permissionsArticle Views4691Altmetric-Citations50LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum full text article downloads since November 2008 (both PDF HTML) across all institutions individuals. These metrics regularly updated to reflect usage leading up last few days.Citations number other articles citing this article, calculated Crossref daily. Find more information about citation counts.The Altmetric Attention Score is a quantitative measure attention that research has received online. Clicking on donut icon will load page at altmetric.com with additional details score social media presence given article. how calculated. Share Add toView InAdd Full Text ReferenceAdd Description ExportRISCitationCitation abstractCitation referencesMore Options onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose SUBJECTS:Air pollution,Atmospheric chemistry,Environmental pollution,Organic compounds,Particulate matter Get e-Alerts

Язык: Английский

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Numerical modelling of ammonia-coal co-firing in a pilot-scale fluidized bed reactor: Influence of ammonia addition for emissions control

Energy Conversion and Management, Год журнала: 2022, Номер 254, С. 115226 - 115226

Опубликована: Янв. 15, 2022

Язык: Английский

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Chemistry and human exposure implications of secondary organic aerosol production from indoor terpene ozonolysis

Science Advances, Год журнала: 2022, Номер 8(8)

Опубликована: Фев. 25, 2022

Surface cleaning using commercial disinfectants, which has recently increased during the coronavirus disease 2019 pandemic, can generate secondary indoor pollutants both in gas and aerosol phases. It also affect air quality health, especially for workers repeatedly exposed to disinfectants. Here, we cleaned floor of a mechanically ventilated office room cleaner while concurrently measuring gas-phase precursors, oxidants, radicals, oxidation products, aerosols real-time; these were detected within minutes after application. During cleaning, monoterpene concentrations exceeded outdoor by two orders magnitude, increasing rate ozonolysis under low (<10 ppb) ozone levels. High number freshly nucleated sub–10-nm particles (≥10 5 cm −3 ) resulted respiratory tract deposited dose rates comparable or exceeding that inhalation vehicle-associated aerosols.

Язык: Английский

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A Fully Integrated Flexible Tunable Chemical Sensor Based on Gold-Modified Indium Selenide Nanosheets

ACS Sensors, Год журнала: 2022, Номер 7(4), С. 1183 - 1193

Опубликована: Апрель 5, 2022

In this work, a novel light-modulated bifunctional gas sensor based on Au nanoparticles-modified 2D InSe nanosheets was demonstrated. The prepared displayed reversible and extremely high response for recognition of nitrogen dioxide (NO2) under visible-light illumination. sensitivity (1192%) about 10 times higher than that dark condition, the limit detection (LOD) 0.17 ppb. contrast, when sensing ammonia (NH3), selectivity were obtained in darkness rather light, with LOD 11% 0.2 ppm. Furthermore, possesses decent stability, repeatability, anti-interference ability. tunable behavior light modulation has been clearly studied help density functional theory. A new principle called "carrier storage box" nanoparticles proposed to explain change surface state modulation. Finally, successfully applied construct fully integrated wearable device measure NH3 NO2 ambient environment. all, work provides highly competitive method paves way designing materials-based optoelectronic devices multifunctional features.

Язык: Английский

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Recent Advances in Ammonia Electrolysis for Sustainable Hydrogen Generation

ACS Sustainable Chemistry & Engineering, Год журнала: 2024, Номер 12(35), С. 13030 - 13047

Опубликована: Июль 25, 2024

Advancing sustainable and clean energy technology is crucial in addressing the current environmental crisis. Hydrogen has garnered significant attention as an carrier due to its abundance, high density, zero carbon emissions. Given challenges associated with hydrogen storage transportation, electrolysis of ammonia presents potential for renewable energy. This process offers a promising solution that meets both supply needs protection goals it serves carbon-free fuel content. However, comprises sluggish oxidation reaction (AOR), understanding complex mechanisms intermediates involved AOR necessary. The development sustainable, low-cost, efficient catalysts plays important role accelerating kinetics boosting performance process. review summarizes state art on aqueous mechanisms, heterogeneous including platinum (Pt), Pt-based alloys, transition-metal-based catalysts, along their using various strategies. Finally, perspectives opportunities future are discussed.

Язык: Английский

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A Source of the Mysterious m/z 36 Ions Identified: Implications for the Stability of Water and Unusual Chemistry in Microdroplets

ACS Central Science, Год журнала: 2025, Номер unknown

Опубликована: Апрель 4, 2025

Many unusual reactions involving aqueous microdroplets have been reported, including nitrogen fixation at room temperature, production of abundant hydrogen peroxide, and formation an ion m/z 36, attributed to (H2O-OH2)+•, (H3O + OH)+•, or (H2O)2 +•, which was used support the hypothesis spontaneous hydroxyl radicals. Here, 36 ions extensive hydrated clusters this are formed using either nanoelectrospray ionization a vibrating mesh nebulizer that produces water droplets ranging from ∼100 nm ∼20 μm. Exhalation single breath near leads substantial increase in abundance series, whereas purging source with N2 gas its complete disappearance. Accurate mass measurements show pure NH4 +(H2O) not +•. Both high sensitivity trace levels gaseous ammonia (unoptimized detection limit low parts-per-billion) these experiments likely misidentification many previous indicate results hypotheses about chemistry effects intrinsic electric fields microdroplet surfaces may require more thorough evaluation.

Язык: Английский

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