Formation of Active Chlorine Oxidants in Saline-Oxone Aerosol

Abstract

The application of oxidative reactions of Oxone R [2KHSO 5 KHSO 4 K 2 SO 4 ] as an active decontaminant has been mainly utilized through the aqueous solution. However, little is known about reactivity of aerosolized Oxone particles although the use of appropriate aerosolized oxidants would have significant value in remediating contaminated surfaces. In this study, the feasibility of producing active chlorine species from saline-Oxone aerosols was studied using a 2-m 3 Teflon film chamber. To evaluate the oxidative capability of a saline-Oxone aerosol, the aerosol was collected onto filters impregnated with a dye (e.g., metanil yellow) that reacts with active chlorine in the aerosol, and monitored by UV-Visible spectroscopy. Spectral data showed that the dye compound was 86% oxidized by active chlorine within 4 min. There was no significant difference in oxidation capability between with buffer and without buffer system, although the presence of phosphate buffer somewhat retarded the formation rate of active chlorine in salineOxone aerosol particles. Saline-Oxone aerosols were found to be highly acidic as determined by UV-Vis spectroscopy, indicating that the aerosol produced mostly an undissociated form of active chlorine species (e.g., HOCl and Cl 2 ) that was susceptible to partitioning into the gas phase. Our study concludes that the aerosolized saline-Oxone is a feasible chlorine oxidant, but the efficiency of such an approach still needs investigation.

Dynamic light absorption of biomass-burning organic carbon photochemically aged under natural sunlight

“…FTIR spectra of aerosols on the disk were obtained under varying relative humidity from 10 to 85 %. Detailed descriptions of the methods can be found in the previous study by Jang et al (2010). Particle concentrations and particle size distributions were monitored continuously using a scanning mobility particle sizer (model 3080, TSI Inc.) together with a condensation nuclei counter (model 3025A, TSI Inc.…”

“…To investigate the hygroscopicity of wood smoke particle, the water content of the particle was monitored using the FTIR equipped with a miniature flow chamber under varying RHs (Jang et al, 2010). The absorbance at 1650 cm −1 , which is the characteristic frequency for O-H bending of water, was used to estimate the water content in the aerosol.…”

Modeling atmospheric mineral aerosol chemistry to predict heterogeneous photooxidation of SO<sub>2</sub>

“…ATD contains hygroscopic inorganic salts that form the thin water film on the surface of ATD particles when the salts are deliquescent (or above ERH). Some salts such as magnesium sulfate and calcium sulfate can be hydrated even at low humidity (Beardsley et al, 2013;Jang et al, 2010). Gustafsson et al (2005) reported that ATD particles showed a substantially high affinity to water compared to pure CaCO 3 particles.…”

Supplementary material to "Modeling of Gas-Wall Partitioning of Organic Compounds Using a Quantitative Structure–Activity Relationship"

“…Madison, WI, USA) interfaced with a specifically fabricated optical flow chamber by controlling the relative humidity in the range from 0.1 to 0.8. Humidity was controlled by combining humid air from a water bubbler and dry air from a dry air tank (Jang et al, 2010;Beardsley et al, 2013;Zhong and Jang, 2014). Calibration curves for water content (Mwall-water, mg m -3 ) of OMwall were obtained by the same method as Jang et al (2010).…”

“…Humidity was controlled by combining humid air from a water bubbler and dry air from a dry air tank (Jang et al, 2010;Beardsley et al, 2013;Zhong and Jang, 2014). Calibration curves for water content (Mwall-water, mg m -3 ) of OMwall were obtained by the same method as Jang et al (2010). The FTIR absorbance of the water peak (Abswater, 3350 cm -1 ) at different RH and the water mass fraction predicted from an inorganic thermodynamic model were related to determine the calibration curve.…”