Transport and fate of reactive trace gases in red spruce needles. 1. Uptake of gaseous hydrogen peroxide as measured in controlled chamber flux experiments

1993 ◽  
Vol 27 (12) ◽  
pp. 2585-2592 ◽  
Author(s):  
Candis S. Claiborn ◽  
Viney P. Aneja
2011 ◽  
Vol 11 (10) ◽  
pp. 28563-28586 ◽  
Author(s):  
Y. Zhao ◽  
Z. M. Chen ◽  
X. L. Shen ◽  
D. Huang

Abstract. Atmospheric aging and processing appears to alter physical and chemical properties of mineral dust aerosol and thus its role as reactive surface in the troposphere. Yet, previous studies in the atmosphere have mainly focused on the clean surfaces of mineral dust aerosol, and the reactivity of aged mineral aerosol toward atmospheric trace gases is still poorly recognized. This work presents the first laboratory investigation of heterogeneous reactions of gaseous hydrogen peroxide (H2O2), an important atmospheric oxidant, on the surface of HNO3 and SO2-processed alumina particles as surrogates of mineral dust aerosol aged by acidic trace gases as a function of relative humidity (RH) and surface coverage of coatings. Pretreatment of the alumina surfaces with HNO3 and SO2 has a strong impact on its reactivity toward H2O2 uptake. On HNO3-processed particles, because of the dual role of the nitrate coating in modifying the reactivity of the particle surface, namely blocking oxide active sites but altering surface hygroscopicity, H2O2 uptake seems to decrease in some cases whereas increase in other cases, largely depending on RH and surface coverage of nitrate. On SO2-processed particles, the presence of adsorbed S(IV) species appears to enhance the intrinsic reactivity of the alumina particles due to its affinity for H2O2, and the uptake of H2O2 increases by 40–80% in the range of RH from 25% to 92% relative to the unprocessed particles. However, when S(IV) is completely oxidized to S(VI), the alumina surface is significantly deactivated and the measured uptake of H2O2 decreased markedly. The mechanisms for heterogeneous reactions of H2O2 with these processed particles are discussed, as well as its potential implications on tropospheric chemistry. The results of our study suggest that the reactivity of mineral dust aerosol toward H2O2 and maybe other atmospheric trace gases will depend on the chemical nature and coverage of the coatings as well as ambient RH, and thus will vary considerably in different polluted atmosphere, which should be taken into account in current atmospheric models.


Tellus B ◽  
1990 ◽  
Vol 42 (2) ◽  
pp. 183-199 ◽  
Author(s):  
Christine A. Ennis ◽  
Allan L. Lazrus ◽  
Patrick R. Zimmerman ◽  
Russell K. Monson

Tellus B ◽  
1990 ◽  
Vol 42 (2) ◽  
pp. 183-199 ◽  
Author(s):  
CHRISTINE A. ENNIS ◽  
ALLAN L. LAZRUS ◽  
PATRICK R. ZIMMERMAN ◽  
RUSSELL K. MONSON

2017 ◽  
Vol 71 (11) ◽  
pp. 778-778
Author(s):  
Céline Pascale ◽  
Daiana Leuenberger ◽  
Myriam Guillevic ◽  
Andreas Ackermann ◽  
Bernhard Niederhauser

2021 ◽  
Author(s):  
Roland Potthast ◽  
Wolfgang Müller ◽  
Barbara Früh ◽  
Peter Korn ◽  
Susanne Brienen ◽  
...  

<p>ICON-seamless entwickelt ein neues Erdsystemmodell, als Grundlage für Wettervorhersage, saisonale und dekadische Klimavorhersagen, bis hin zu Klimaprojektionen. Dabei nutzen wir die Expertise, die ICON-NWV als zuverlässiges Modell für numerische Wettervorhersage (NWV) betreibt und pflegt sowie die Erfahrungen mit der ersten ICON-Erdsystemversion basierend auf der Physik der MPI-Atmosphäre ECHAM. Das Ziel ist, gemeinsame Komponenten für alle meteorologischen Zeitskalen nutzen zu können. Der erste Schritt entwickelt ein Modell für saisonale und dekadische Zeitskalen.</p> <p>ICON-seamless baut auf der Kopplung der Komponenten ICON-NWV (Atmosphäre) und ICON-O (Ozean) auf. Mit Hilfe des speziell entwickelten Kopplungs-Tools YAC können beide Komponenten Variablen austauschen, die für die Wechselwirkung zwischen Atmosphäre und Ozean wichtig sind. Auch die Parametrisierung von Meereis stellt einen wichtigen Baustein dar. Zur Wiedergabe eines geschlossenen hydrologischen Kreislaufs und um den Kohlenstoffkreislauf sauber darzustellen, wird ferner ein geeignetes Bodenmodell, ICON-L, an die Atmosphärenphysik von ICON-NWV gekoppelt. Zudem werden transiente Aerosolfelder, Treibhausgase, und Strahlungsantriebe neu in ICON-NWV eingelesen, um historische Zeiträume nachzuvollziehen. Parallel hierzu werden die ART Module (Aerosol and Reactive Trace gases), die eine dynamische Behandlung von Gasen und Aerosolen gestatten, an die modifizierte Modellphysik angepasst. Eine intensive Modelldiagnostik unterstützt das Tuning. Für die zukünftige Verwendung im Bereich der (Wetter- und) Klimavorhersagen wird parallel die gekoppelte Datenassimilation entwickelt.</p> <p>Wir geben einen Überblick über den aktuellen Stand der Entwicklung, der Experimente und potentieller Anwendungsbereiche.</p>


2016 ◽  
Vol 57 (4) ◽  
pp. 45-51 ◽  
Author(s):  
Zbigniew Dąbrowiecki ◽  
Małgorzata Dąbrowiecka ◽  
Romuald Olszański ◽  
Piotr Siermontowski

AbstractWhen working in chemical or biological environments, contamination is an extremely dangerous issue for the rescue services of the fire department, police and the army.Modern protective overalls worn by fire fighters or dry “Viking” diving suits made from neoprene or nylon covered with polyurethane, have been proven to ensure sufficient protection. However, once the contaminated area is left, there is a need to perform decontamination of the external and internal surfaces of the protective overalls; in order to ensure the clothing continues to offer a high level of comfort and to retain the durability of said protective clothing, it is of course also necessary to perform a drying procedure.Moreover, there is a risk of a transfer of pathogenic micro-organisms between persons utilising the same protective clothes, particularly in the case of expensive specialist suits. Micro-organisms which may potentially spread through clothing include intestinal bacteria, such as: Salmonella, Shigella, Campylobacter, E. coli (including E. coli O157), C. difficile, viruses inducing infections of the upper respiratory tract and alimentary tract (noraviruses, rotaviruses, adeno and astroviruses). The risk of infection also involves the presence of the flu viruses, herpesviruses and pathogens transferred through skin, such as S. aureus (including MRSA), yeast-like fungi (Candida albicans), fungal strains inducing Tinea pedis and Tinea corporis [1]. Pathogenic micro-organisms can easily transfer from fabric surface onto the body of a person wearing protective clothing.From the numerous available techniques of decontamination of surfaces, equipment and protective clothing we propose to use for this purpose gaseous hydrogen peroxide (H2O2), a very effective biocidal agent. In field conditions, typical for the activities of rescue crews of the fire department, police and army we assume utilisation of a portable decontamination chamber enabling performance of a complete decontamination process.The process lasting approximately 3 hours encompasses 3 phases:• Drying phase;• Decontamination with gaseous hydrogen peroxide;• Catalytic combustion phase of hydrogen peroxide residues to a level safe for the environment.The integrated humidity and H2O2level sensors ensure automatic control of the entire process and the unique distribution system of gaseous H2O2secures full accessibility of the biocidal agent to the external surface of protective clothing as well as its interior. Moreover, the container allows for the conduction of the complete decontamination of the rescue equipment, night vision devices, binoculars, field telephones, radio stations, etc. Upon decontamination cycle completion, we obtain a completely dried suit which can be safely used by another crew member.


2022 ◽  
pp. 147-169
Author(s):  
Narendra Ojha ◽  
Imran Girach ◽  
Meghna Soni ◽  
Narendra Singh

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