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

2020 ◽  
Vol 54 (15) ◽  
pp. 9629-9639 ◽  
Author(s):  
Devon Manley Bulman ◽  
Christina K. Remucal
Keyword(s):  
Disinfection Byproduct ◽  
Reactive Halogen Species ◽  
Byproduct Formation ◽  
Halogen Species

scholarly journals Chemical interactions between ship-originated air pollutants and ocean-emitted halogens

2021 ◽  
Author(s):  
Qinyi Li ◽  
Alba Badia ◽  
Rafael P. Fernandez ◽  
Anoop S. Mahajan ◽  
Ana Isabel López-Noreña ◽  
...  
Keyword(s):  
Air Pollutants ◽  
Atmospheric Composition ◽  
Chemical Transformations ◽  
Chemical Interactions ◽  
China Sea ◽  
Reactive Halogen Species ◽  
The Impact ◽  
Surface Increase ◽  
Halogen Species

<p>Ocean-going ships supply products from one region to another and contribute to the world’s economy. Ship exhaust contains many air pollutants and results in significant changes in marine atmospheric composition. The role of Reactive Halogen Species (RHS) in the troposphere has received increasing recognition and oceans are the largest contributors to their atmospheric burden. However, the impact of shipping emissions on RHS and that of RHS on ship-originated air pollutants have not been studied in detail. Here, an updated WRF-Chem model is utilized to explore the chemical interactions between ship emissions and oceanic RHS over the East Asia seas in summer. The emissions and resulting chemical transformations from shipping activities increase the level of NO and NO<sub>2</sub> at the surface, increase O<sub>3</sub> in the South China Sea, but decrease O<sub>3</sub> in the East China Sea. Such changes in pollutants result in remarkable changes in the levels of RHS as well as in their partitioning. The abundant RHS, in turn, reshape the loadings of air pollutants and those of the oxidants with marked patterns along the ship tracks. We, therefore, suggest that these important chemical interactions of ship-originated emissions with RHS should be considered in the environmental policy assessments of the role of shipping emissions in air quality and climate.</p>

scholarly journals Photochemical chlorine and bromine activation from artificial saline snow

2013 ◽  
Vol 13 (19) ◽  
pp. 9789-9800 ◽  
Author(s):  
S. N. Wren ◽  
D. J. Donaldson ◽  
J. P. D. Abbatt
Keyword(s):  
Gas Phase ◽  
High Surface ◽  
High Surface Area ◽  
Ionization Mass ◽  
Heterogeneous Oxidation ◽  
Reactive Halogen Species ◽  
Explosion Mechanism ◽  
Halogen Species ◽  
Snow Samples

Abstract. The activation of reactive halogen species – particularly Cl2 – from sea ice and snow surfaces is not well understood. In this study, we used a photochemical snow reactor coupled to a chemical ionization mass spectrometer to investigate the production of Br2, BrCl and Cl2 from NaCl/NaBr-doped artificial snow samples. At temperatures above the NaCl-water eutectic, illumination of samples (λ > 310 nm) in the presence of gas phase O3 led to the accelerated release of Br2, BrCl and the release of Cl2 in a process that was significantly enhanced by acidity, high surface area and additional gas phase Br2. Cl2 production was only observed when both light and ozone were present. The total halogen release depended on [ozone] and pre-freezing [NaCl]. Our observations support a "halogen explosion" mechanism occurring within the snowpack, which is initiated by heterogeneous oxidation and propagated by Br2 or BrCl photolysis and by recycling of HOBr and HOCl into the snowpack. Our study implicates this important role of active chemistry occurring within the interstitial air of aged (i.e. acidic) snow for halogen activation at polar sunrise.

scholarly journals Enhancement of Photo-bromination of Phenol by Anthraquinone-2-sulphonate and Benzophenone: Implication for Photo-production of Organic Brominated Compounds by Dissolved Organic Matter in Marine Environment

2021 ◽  
Author(s):  
Hui Liu ◽  
Xiaojun Qiu ◽  
Xiaomei Zhu ◽  
Bing Sun ◽  
Xiaoxing Zhang
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Marine Environment ◽  
Bromide Solution ◽  
Reactive Halogen Species ◽  
Organohalogen Compounds ◽  
Halogenation Reaction ◽  
Photo Production ◽  
Halogen Species

Abstract Organobromine compounds are of great ecological risks due to their high toxicity on organisms. Photochemical halogenation reaction may represent an important natural formation process of natural organobromine compounds in marine environment. Here we reported the enhanced formation of bromophenols from phenol by sunlit anthraquinone-2-sulphonate (AQ2S) and benzophenone (BP) in aqueous bromide solutions. Quinones and aromatic ketones are ubiquitous components of dissolved organic matter (DOM) in surface waters, and AQ2S and BP were adopted here as proxies of DOM. Bromophenols’ formation increased with the increasing of the concentrations of AQ2S and BP, and the promotion effect was in the order AQ2S > BP, indicating that sunlit DOM plays an important role for the formation of reactive bromine species. Chloride was found to promote the formation of bromophenols obviously, suggesting a possible role of the mixed reactive halogen species. Finally, the natural DOM from Suwannee River was found to enhance photobromoination at a low concentration (1 mg L-1) in aqueous bromide solution. Our results demonstrated the importance of reactive halogen species generation from sunlit DOM, which possibly contributes to the abiotic source of organohalogen compounds in marine environment.

Making Swimming Pools Safer: Does Copper–Silver Ionization with Chlorine Lower the Toxicity and Disinfection Byproduct Formation?

2021 ◽  
Vol 55 (5) ◽  
pp. 2908-2918
Author(s):  
Joshua M. Allen ◽  
Michael J. Plewa ◽  
Elizabeth D. Wagner ◽  
Xiao Wei ◽  
Gretchen E. Bollar ◽  
...  
Keyword(s):  
Swimming Pools ◽  
Disinfection Byproduct ◽  
Byproduct Formation

Iodinated disinfection byproduct formation in a MnO2/I−/EPS system

Chemosphere ◽  
2021 ◽  
pp. 130643
Author(s):  
Lingxiao Fu ◽  
Xiaofeng Wu ◽  
Yongbin Zhu ◽  
Lei Yao ◽  
Chengqiang Wu ◽  
...  
Keyword(s):  
Disinfection Byproduct ◽  
Byproduct Formation

scholarly journals Numerical analysis of the chemical kinetic mechanisms of ozone depletion and halogen release in the polar troposphere

2013 ◽  
Vol 13 (9) ◽  
pp. 24171-24222 ◽  
Author(s):  
L. Cao ◽  
H. Sihler ◽  
U. Platt ◽  
E. Gutheil
Keyword(s):  
Boundary Layer ◽  
Surface Area ◽  
Ozone Depletion ◽  
Reaction Rates ◽  
The Arctic ◽  
Strong Impact ◽  
Reactive Surface ◽  
A Value ◽  
Halogen Species

Abstract. In recent years, the role of halogen species (e.g. Br, Cl) in the troposphere of polar regions is investigated after the discovery of their importance for boundary layer ozone destruction in the polar spring. Halogen species take part in an auto-catalytic chemical cycle including key self reactions. In this study, several chemical reaction schemes are investigated, and the importance of specific reactions and their rate constants is identified by a sensitivity analysis. A category of heterogeneous reactions related to HOBr activate halogen ions from sea salt aerosols, fresh sea ice or snow pack, driving the "bromine explosion". In the Arctic, a small amount of NOx may exist, which comes from nitrate contained in the snow, and this NOx may have a strong impact on ozone depletion. The heterogeneous reaction rates are parameterized by considering the aerodynamic resistance, a reactive surface ratio, β, i.e. ratio of reactive surface area to total ground surface area, and the boundary layer height, Lmix. It is found that for β = 1, the ozone depletion process starts after five days and lasts for 40 h for Lmix = 200 m. Ozone depletion duration becomes independent of the height of the boundary layer for about β≥20, and it approaches a value of two days for β=100. The role of nitrogen and chlorine containing species on the ozone depletion rate is studied. The calculation of the time integrated bromine and chlorine atom concentrations suggests a value in the order of 103 for the [Br] / [Cl] ratio, which reveals that atomic chlorine radicals have minor direct influence on the ozone depletion. The NOx concentrations are influenced by different chemical cycles over different time periods. During ozone depletion, the reaction cycle involving the BrONO2 hydrolysis is dominant. A critical value of 0.002 of the uptake coefficient of the BrONO2 hydrolysis reaction at the aerosol and saline surfaces is identified, beyond which the existence of NOx species accelerate the ozone depletion event – for lower values, deceleration occurs.

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