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The treatment and detection of ozone have been widely studied in recent decades with respect to toxicity and contamination, while the measurement method of ozone is relatively toneless. Fortunately, a new concept of the cataluminescence (CTL) sensor provides a scheme of real-time ozone sensing in a tiny system. Here, a novel CTL sensor system was specially developed with silica-hydroxyl functional boron nitride as the sensing material for rapid and sensitive ozone detection. Coupled with the construction of a pulse vacuum static sampling system, ozone on the surface of sensing material can be desorbed rapidly and can step into the next detection circulation in a few seconds. Based on the strong emission initiated by the transient of reactive oxygen species (ROS) including singlet oxygen, a trioxide group, and an oxygen radical, the detection limit of ozone could be optimized to be as low as 51.2 ppb. Besides, the sensor system exhibited remarkable anti-interference performance in which humidity changes and common VOCs do not disturb or weakly disturb ozone sensing, and the CTL mechanism of the multistep degradation process was further discussed on the basis of multiple pieces of experimental evidence and a DFT transient calculation. A real-time degradation-sensing module was further attached to the system to realize the functions of ozone decomposition and real-time monitoring.

We present a novel combination of a metal oxide laser ionization mass spectrometry imaging (MOLI MSI) technique with off-line lipid derivatization by ozone for the detection of fatty acids (FA) and their carbon-carbon double bond (C═C) positional isomers in biological tissues. MOLI MSI experiments were realized with CeO

This study investigated catalytic decomposition and mass transfer of aqueous ozone promoted by Fe-Mn-Cu/γ-Al2O3 (Cat) in a rotating packed bed (RPB) for the first time. The results showed that the value of the overall decomposition rate constant of ozone (Kc) and overall volumetric mass transfer coefficient (KLa) are 4.28×10−3 s−1 and 11.60×10−3 s−1 respectively at an initial pH of 6, β of 40, C O 3 ( g ) of 60 mg·L−1 and QL of 85 L·h−1 in deionized water, respectively. Meanwhile, the Kc and KLa values of Fenhe water are 0.88×10−3 s−1 and 2.51×10−3 s−1 lower than deionized water, respectively. In addition, the Kc and KLa values in deionized water for the Cat/O3-RPB system are 44.86% and 47.41% higher than that for the Cat/O3-BR (bubbling reactor) system, respectively, indicating that the high gravity technology can facilitate the decomposition and mass transfer of ozone in heterogeneous catalytic ozonation and provide some insights into the industrial wastewater.

We present a novel sensing approach for ambient ozone detection based on deep-ultraviolet (DUV) cavity-enhanced absorption spectroscopy (CEAS) using a laser driven light source (LDLS). The LDLS has broadband spectral output which, with filtering, provides illumination between ~230–280 nm. The lamp light is coupled to an optical cavity formed from a pair of high-reflectivity (R~0.99) mirrors to yield an effective path length of ~58 m. The CEAS signal is detected with a UV spectrometer at the cavity output and spectra are fitted to yield the ozone concentration. We find a good sensor accuracy of

O3 and free chlorine play significant roles in disinfection and organic degradation.

Organic nitrate (RONO2) formation in the atmosphere represents a sink of NOx (NOx = NO + NO2) and termination of the NOx/HOx (HOx = HO2 + OH) ozone formation and radical propagation cycles, can act as a NOx reservoir transporting reactive nitrogen, and contributes to secondary organic aerosol formation. While some fraction of RONO2 is thought to reside in the particle phase, particle-phase organic nitrates (pRONO2) are infrequently measured and thus poorly understood. There is an increasing prevalence of aerosol mass spectrometer (AMS) instruments, which have shown promise for determining the quantitative total organic nitrate functional group contribution to aerosols. A simple approach that relies on the relative intensities of NO+ and NO2+ ions in the AMS spectrum, the calibrated NOx+ ratio for NH4NO3, and the inferred ratio for pRONO2 has been proposed as a way to apportion the total nitrate signal to NH4NO3 and pRONO2. This method is increasingly being applied to field and laboratory data. However, the methods applied have been largely inconsistent and poorly characterized, and, therefore, a detailed evaluation is timely. Here, we compile an extensive survey of NOx+ ratios measured for various pRONO2 compounds and mixtures from multiple AMS instruments, groups, and laboratory and field measurements. All data and analysis presented here are for use with the standard AMS vaporizer. We show that, in the absence of pRONO2 standards, the pRONO2 NOx+ ratio can be estimated using a ratio referenced to the calibrated NH4NO3 ratio, a so-called “Ratio-of-Ratios” method (RoR = 2.75 ± 0.41). We systematically explore the basis for quantifying pRONO2 (and NH4NO3) with the RoR method using ground and aircraft field measurements conducted over a large range of conditions. The method is compared to another AMS method (positive matrix factorization, PMF) and other pRONO2 and related (e.g., total gas + particle RONO2) measurements, generally showing good agreement/correlation. A broad survey of ground and aircraft AMS measurements shows a pervasive trend of higher fractional contribution of pRONO2 to total nitrate with lower total nitrate concentrations, which generally corresponds to shifts from urban-influenced to rural/remote regions. Compared to ground campaigns, observations from all aircraft campaigns showed substantially lower pRONO2 contributions at midranges of total nitrate (0.01–0.1 up to 2–5 µg m−3), suggesting that the balance of effects controlling NH4NO3 and pRONO2 formation and lifetimes – such as higher humidity, lower temperatures, greater dilution, different sources, higher particle acidity, and pRONO2 hydrolysis (possibly accelerated by particle acidity) – favors lower pRONO2 contributions for those environments and altitudes sampled.

The generation of ozone and nitrogen oxides by laser-induced dielectric breakdown (LIDB) in mixtures of air with noble gases Ar, He, Kr, and Xe is investigated using OES and IR spectroscopy, mass spectrometry, and absorption spectrophotometry. It is shown that the formation of NO and NO2 noticeably depends on the type of inert gas; the more complex electronic configuration and the lower ionization potential of the inert gas led to increased production of NO and NO2. The formation of ozone occurs mainly due to the photolytic reaction outside the gas discharge zone. Equilibrium thermodynamic analysis showed that the formation of NO in mixtures of air with inert gases does not depend on the choice of an inert gas, while the equilibrium concentration of the NO+ ion decreases with increasing complexity of the electronic configuration of an inert gas.

The inactivation time for the SARS CoV-2 virus, mostly by a portion of UVB spectrum (290–315 nm) in sunlight, has been estimated using radiative transfer calculations and a relative wavelength sensitivity virus inactivation action spectrum ALS. The action spectrum is adjusted for the SARS CoV-2 virus using a derived UV dose D90 = 3.2 J/m2 for 90% inactivation to match laboratory results for the inactivation of SARS CoV-2 virus droplets on steel mesh. Estimation of the time for 90% inactivation T90 at a specific geographic location can be simplified using the commonly published or calculated UV index (UVI). The use of UVI has the advantage that information on the amount of ozone, the site altitude, and the degree of cloud cover are built into the published UVI calculation. Simple power-law T90(UVI) = a UVIb fitting equations are derived that provide estimates of T90(UVI) for 270 specific locations. Using the results from the 270 locations, a generalized latitude θ dependence is presented for the coefficients a(θ) and b(θ) that enables T90(θ, UVI) to be estimated for 60°S ≤ θ ≤ 60°N and for noon and 2 h around local solar noon.

Aerosols are a source of great uncertainty in radiative forcing predictions and have poorly understood health impacts. Most aerosol mass is formed in the atmosphere from reactive gas-phase organic precursors, forming secondary organic aerosol (SOA). Semivolatile organic compounds (SVOCs) (effective saturation concentration, C*, of 10−1–103 µg m−3) comprise a large fraction of organic aerosol, while intermediate-volatility organic compounds (IVOCs) (C* of 103–106 µg m−3) and volatile organic compounds (VOCs) (C* ≥ 106 µg m−3) are gas-phase precursors to SOA and ozone. The Comprehensive Thermal Desorption Aerosol Gas Chromatograph (cTAG) is the first single instrument simultaneously quantitative for a broad range of compound-specific VOCs, IVOCs and SVOCs. cTAG is a two-channel instrument which measures concentrations of C5–C16 alkane-equivalent-volatility VOCs and IVOCs on one channel and C14–C32 SVOCs on the other coupled to a single high-resolution time-of-flight mass spectrometer, achieving consistent quantification across 15 orders of magnitude of vapor pressure. cTAG obtains concentrations hourly and gas–particle partitioning for SVOCs every other hour, enabling observation of the evolution of these species through oxidation and partitioning into the particle phase. Online derivatization for the SVOC channel enables detection of more polar and oxidized species. In this work we present design details and data evaluating key parameters of instrument performance such as I/VOC collector design optimization, linearity and reproducibility of calibration curves obtained using a custom liquid evaporation system for I/VOCs and the effect of an ozone removal filter on instrument performance. Example timelines of precursors with secondary products are shown, and analysis of a subset of compounds detectable by cTAG demonstrates some of the analytical possibilities with this instrument.

Zinc oxide (ZnO) has great potential as an electron transport layer (ETL) for producing efficient and stable organic solar cells. The effect of ozone treatment on ZnO working as the ETL in the organic solar cell has been studied by analyzing crystallinity, the defect density of states, and charge carrier dynamics from transient absorption spectroscopy to understand its role in the improvement in the interface between ETL and active layers. We have observed that a 10-minute continuous ozone treatment of ZnO film demonstrates improvement in its crystallinity leading to a 23% increment in short circuit current. The improvement in the crystallinity has been confirmed by the morphological and structural analysis using SEM and GIXRD. These analyses reveal the formation of a flake-like structure and an increase in peak intensity in GIXRD. It has been observed that ozone exposure has significantly affected the carrier recombination resistance, ideality factor of the device. From transient absorption spectroscopy, it has been found that for 10 min ozone-treated ZnO film has an average carrier transport time (661.79 ps), which is smallest as compared to untreated film or over treated film leading to faster carrier extraction through ETL. Further, the study of defect density of states shows that optimized ozone-treated film show 22.08% decrease in defects as compared to the control device, which primarily reflected as the improvement in the current density leading to increase in device efficiency from 2.95% to 3.75%.

Air quality monitoring networks are challenging to implement due to the bulkiness and high prices of the standard instruments and the low accuracy of most of the described low-cost approaches. This paper presents a low-cost, automated, self-powered analytical platform to determine the hourly levels of O3 and NO2 in urban atmospheres. Atmospheric air was sampled at a constant airflow of 100 mL min−1 directly into vials containing 800 µL of indigotris sulfonate and the Griess–Saltzman reagent solutions for ozone and nitrogen dioxide, respectively. The analysis holder, containing a light-emitting diode and a digital light sensor, enabled the acquisition of the analytical signal on-site and immediately after the sampling time. The data were transmitted to a laptop via Bluetooth, rendering remote hourly monitoring. The platform was automated using two Arduino Uno boards and fed with a portable battery recharged with a solar panel. The method provided a limit of detection of 5 and 1 ppbv for O3 and NO2, respectively, which is below the maximum limit established by worldwide regulatory agencies. The platform was employed to determine the levels of both pollutants in the atmosphere of two Brazilian cities, in which one of them was equipped with an official air quality monitoring station. Comparing the results of both techniques revealed suitable accuracy for the proposed analytical platform. Information technology (IT) allied to reliable chemical methods demonstrated high potential to create air quality monitoring networks providing valuable information on pollutants’ emissions and ensuring safety to the population.

In the current study, an integrated physiochemical method was utilized to remove tonalide (TND) and dimethyl phthalate (DMP) (as emerging contaminants, ECs), and nickel (Ni) and lead (Pb) (as heavy metals), from synthetic wastewater. In the first step of the study, pH, current (mA/cm2), and voltage (V) were set to 7.0, 30, and 9, respectively; then the removal of TND, DMP, Ni, and Pb with an electro-ozonation reactor was optimized using response surface methodology (RSM). At the optimum reaction time (58.1 min), ozone dosage (9.4 mg L−1), initial concentration of ECs (0.98 mg L−1), and initial concentration of heavy metals (28.9 mg L−1), the percentages of TND, DMP, Ni, and Pb removal were 77.0%, 84.5%, 59.2%, and 58.2%, respectively. For the electro-ozonation reactor, the ozone consumption (OC) ranged from 1.1 kg to 3.9 kg (kg O3/kg Ecs), and the specific energy consumption (SEC) was 6.95 (kWh kg−1). After treatment with the optimum electro-ozonation parameters, the synthetic wastewater was transferred to a fixed-bed column, which was filled with a new composite adsorbent (named BBCEC), as the second step of the study. BBCEC improved the efficacy of the removal of TND, DMP, Ni, and Pb to more than 92%.

Disorder of lipid homeostasis is closely associated with a variety of diseases. Although mass spectrometry (MS) approaches have been well developed for the characterization of lipids, it still lacks an integrated and compact MS system that is capable of rapid and detailed lipid structural characterization and can be conveniently transferred into different laboratories. In this work, we describe a novel miniature MS system with the capability of both ozone-induced dissociation (OzID) and collision-induced dissociation (CID) for the assignment of sites of unsaturation and

Biogenic volatile organic compounds (BVOCs) contribute the majority of reactive organic carbon to the atmosphere and lead to aerosol formation through reaction with atmospheric oxidants including ozone and hydroxyl radicals. One class of BVOCs, sesquiterpenes, have a high reactivity with ozone but exist at lower concentrations compared to other BVOCs, and there are relatively few measurements of their concentrations in different environments or their importance in the atmospheric oxidant budget. To help close this knowledge gap, we examine concentrations of isomer-resolved sesquiterpene concentrations collected hourly at two sites in Virginia that are representative of different ecosystems in the southeastern US. Sesquiterpene concentrations are presented and discussed in relation to their diurnal patterns and used to estimate their contribution to reactivity with common gas-phase oxidants. Twenty-four sesquiterpenes were identified at the sites, eleven of which were observed at both sites. Total sesquiterpene concentrations were found to range between 0.8 and 2 ppt with no single isomer dominating throughout. Hydroxyl activity is similarly diverse, with no particular isomer dominating activity at either site. Ozone reactivity, however, was found to be dominated (similar to 3/4 total reactivity) by beta-caryophyllene and humulene despite these compounds representing roughly only 10% of total sesquiterpene mass, highlighting their importance as the major driver of sesquiterpene-ozone reactivity. Average reaction rate constants for sesquiterpenes with ozone and hydroxyl radicals were calculated for both sites as a method to simplify future atmospheric modelling concerning sesquiterpenes. This work provides broad insight into the composition and impacts of sesquiterpenes, suggesting that sesquiterpene composition is relatively similar between sites. Furthermore, while the calculated average sesquiterpene-ozone reaction rate constants are at least an order of magnitude higher than that of more prevalent BVOC classes (isoprene and monoterpenes), their low concentrations suggest their impacts on atmospheric reactivity are expected to be limited to periods of high emissions. National Science Foundation [AGS 1837882, AGS 1837891]; Pace Endowment; Virginia Space Grant Consortium Graduate Research Fellowships; Edna Bailey Sussman Foundation Internship Published version This research was funded by the National Science Foundation (AGS 1837882 and AGS 1837891). Tower maintenance and operation were supported in part by the Pace Endowment. Deborah F. McGlynn and Laura E. R. Barry were supported in part by Virginia Space Grant Consortium Graduate Research Fellowships. Graham Frazier was supported in part by the Edna Bailey Sussman Foundation Internship. We would like to thank the reviewers for help in strengthening the presentation of this paper. In particular, we would like to thank reviewer 3 for their advice on formatting of Fig. 2 to better display the data.

An unprecedented route for mitigating the inhibitory effect of lactic acid (LA) on milk fermentation was achieved through lactate adsorption on hydrotalcite (Ht) from simulated lactate extracts. During its regeneration by ozonation, Ht displayed catalytic activity that appeared to increase by addition of montmorillonite (Mt). Changes in the pH, Zeta potential and catalyst particle size during LA ozonation were found to strongly influence LA–LA, LA–catalyst and catalyst–catalyst interactions. The latter determine lactate protonation–deprotonation and clay dispersion in aqueous media. The activity of Mt appears to involve hydrophobic adsorption of non-dissociated LA molecules on silica-rich areas at low pH, and Lewis acid–base and electrostatic interactions at higher pH than the pKa. Hydrotalcite promotes both hydrophobic interaction and anion exchange. Hydrotalcite–smectite mixture was found to enhance clay dispersion and catalytic activity. This research allowed demonstrating that natural clay minerals can act both as adsorbents for LA extract from fermentation broths and as catalysts for adsorbent regeneration. The results obtained herein provide valuable and useful findings for envisaging seed-free milk clotting in dairy technologies.

The negative air ions (NAI) are used for the removal of particles or droplets from the air. In this study, three types of piezoelectric cold plasma generators (PCPG), in combination with cylindrical electrostatic ion filters, are applied for NAI production. The high voltage on the filter cylinder is induced by the electric field from the piezoelectric transformer of the PCPG. To achieve the dc bias, the cylinder of the electrostatic filter is connected to the ground over ultrafast switching diodes. The ion concentrations are measured for different airflows, PCPG powers, and electrostatic filter geometries. The NAI concentration in the order of magnitude of 107 cm−3, and a negative-to-positive ion concentration ratio of over 200 is reached. The production of ozone is evaluated and the PCPG configuration with a minimum ozone production rate is proposed. The ozone concentration below 60 ppb is reached in the airflow of 90 m3/h.

The influence of relative humidity (RH) on the condensational growth of organic aerosol particles remains incompletely understood. Herein, the RH dependence was investigated via a series of experiments for α-pinene ozonolysis in a continuously mixed flow chamber in which recurring cycles of particle growth occurred every 7 to 8 h at a given RH. In 5 h, the mean increase in the particle mode diameter was 15 nm at 0% RH and 110 nm at 75% RH. The corresponding particle growth coefficients, representing a combination of the thermodynamic driving force and the kinetic resistance to mass transfer, increased from 0.35 to 2.3 nm2 s-1. The chemical composition, characterized by O:C and H:C atomic ratios of 0.52 and 1.48, respectively, and determined by mass spectrometry, did not depend on RH. The Model for Simulating Aerosol Interactions and Chemistry (MOSAIC) was applied to reproduce the observed size- and RH-dependent particle growth by optimizing the diffusivities Db within the particles of the condensing molecules. The Db values increased from 5 α-1 × 10-16 at 0% RH to 2 α-1 × 10-12 cm-2 s-1 at 75% RH for mass accommodation coefficients α of 0.1 to 1.0, highlighting the importance of particle-phase properties in modeling the growth of atmospheric aerosol particles.

The oxidation of ozone is very strong, and the products of oxidative decomposition will not cause secondary pollution, so the ozone has become widely used. Dielectric barrier discharge (DBD) is the...

The ozone is a gas composed by three molecules of oxygen which has a great oxidative capacity. This gas can be generated by a nucleus with two electrodes through high voltage in a phenomenon known as corona effect. Actually the conventional nucleus of ozone generators use plane electrodes with a dielectric in the middle of both. A nucleus composed by a mixed ionizador (coil and mesh) is presented as an alternative for an ozone machine in order to take advantage of the individual benefits of each electrode due to its shape and efficiency. A solenoid acts better without dielectric, reducing the consumption, and a mesh improves the air flux. As a result, there is a good production of ozone using this combination of electrodes. However, there are no studies that demonstrate that it is possible to use different types of electrodes in the same ionizador, for this reason in this study will be detected the production of ozone by corona effect in the proposed nucleus and will be approximated its concentration in a closed volume. Keywords: Ozone, corona effect, high voltage, generator, ionization. Resumen El ozono es un gas compuesto por tres moléculas de oxígeno que tiene una gran capacidad oxidativa. Este gas puede ser generado en un núcleo con dos electrodos mediante el uso de altos voltajes en un fenómeno conocido como efecto corona. Actualmente los núcleos de los generadores de ozono convencionales utilizan electrodos planos con un dieléctrico en medio de ellos. Un núcleo compuesto por un ionizador mixto (bobina y malla) se presenta como una alternativa para un ozonificador, con el fin de aprovechar las ventajas individuales de cada electrodo debido a su forma y eficiencia. Un solenoide actúa mejor sin dieléctrico, disminuyendo el consumo, y una malla mejora el flujo de aire. Lo que resulta en una buena producción de ozono utilizando esta combinación de electrodos. Sin embargo, no existen estudios anteriores que demuestran que se puede utilizar diferentes tipos de electrodos en un mismo ionizador, por esta razón en el presente estudio se detectará la producción de ozono por efecto corona en el núcleo mixto propuesto y aproximamos su concentración en un volumen cerrado. Palabras Clave: Ozono, efecto corona, alto voltaje, generador, ionización.

A non-thermal plasma (NTP) reactor was used to generate ozone for diesel particulate filter (DPF) regeneration. The kinetic mechanism of ozone thermal decomposition reaction is explored, and the effect of temperature on the change of ozone concentration is analyzed. The changes of the internal temperature and the concentration of regeneration products such as CO2 and CO during the regeneration under constant temperature and non-constant temperature conditions are then studied and the influence of different regeneration environments on the regeneration is analyzed in combination with the decomposition law of ozone. In the non-constant temperature condition, DPF surface temperature changes significantly with time. The results show that when using an NTP reactor to generate ozone, the activation energy of the decomposition reaction is 2.80755 × 104 J/mol and the law of thermal decomposition reaction can be described as $$k = 190.76 \times {e^{( - 2.80755 \times {{10}^4}/RT)}}$$ . During DPF regeneration, the overall regeneration rate and ozone utilization rate in the non-constant temperature environment are higher than in the constant temperature environment and the temperature change (delta-T) peak rises with the increase of PM deposition. The regeneration with NTP under non-constant thermal condition is an effective way to improve the efficiency of DPF regeneration.

A green analytical method for the determination of Cu and Zn in rice samples was developed. This method was based on an ozone-assisted extraction (OAE) in diluted acid media. A novel closed system was designed for this purpose that allowed four simultaneous sample treatments being safe for the laboratory environment. The method consisted in 0.5 g of the sample, 15 minutes of ozonation, and 3 minutes of centrifugation. The obtained supernatant was ready for Cu and Zn determinations by flame atomic absorption spectrometry. Detection limits were 0.20 and 0.08 mg kg−1 for Cu and Zn, respectively, with a precision (RSD) better than 5% for both elements. A certified reference material of rice flour was analyzed for trueness evaluation, and the mean recoveries (%) were 100.4 (Cu) and 95.9 (Zn). Several commercial rice samples were analyzed using this method, and the results were compared with those obtained using traditional microwave-assisted digestion (MAE). Both methods yielded comparable results. Cu and Zn levels were in accordance with reported values in other regions. The OAE resulted to be simple and economical and with results equivalent with those obtained using traditional sample preparation procedures as MAE with the advantage of being in good agreement with the principles of green analytical chemistry.

Mass spectrometry imaging (MSI) of lipids within tissues has significant potential for both biomolecular discovery and histopathological applications. Conventional MSI technologies are, however, challenged by the prevalence of phospholipid regioisomers that differ only in the location(s) of carbon-carbon double bonds and/or the relative position of fatty acyl attachment to the glycerol backbone (i.e., sn position). The inability to resolve isomeric lipids within imaging experiments masks underlying complexity, resulting in a critical loss of metabolic information. Herein, ozone-induced dissociation (OzID) is implemented on a mobility-enabled quadrupole time-of-flight (Q-TOF) mass spectrometer capable of matrix-assisted laser desorption/ionization (MALDI). Exploiting the ion mobility region in the Q-TOF, high number densities of ozone were accessed, leading to similar to 1000-fold enhancement in the abundance of OzID product ions compared to earlier MALDI-OzID implementations. Translation of this uplift into imaging resulted in a 50-fold improvement in acquisition rate, facilitating large-area mapping with resolution of phospholipid isomers. Mapping isomer distributions across rat brain sections revealed distinct distributions of lipid isomer populations with region-specific associations of isomers differing in double bond and sn positions. Moreover, product ions arising from sequential ozone- and collision-induced dissociation enabled double bond assignments in unsaturated fatty acyl chains esterified at the noncanonical sn-1 position.

The dissolution of concentrated ozone in water at liquid and gas counter-flows has been studied. It was shown that the ozone flow rate can be increased from 0.042 cm3/s cm2 (flotation treatment of water with ozone) to 3.6 cm3/s cm2 (counter-flow). A scheme of counter-mixing of ozone in gas with water without using flotation technology was suggested. The optimum ratio of ozone carrier gas to water was found to be 1 : 3. The ozone concentration at the reactor outlet was 8 mg/dm3 (4%), and the concentration of ozone dissolved in water reached 45 mg/dm3. A scheme of a unit for counter-mixing of ozone in gas with water was proposed.

As a standard method for measuring the concentration of carbonyl compounds in air, 2,4-dinitrophenylhydrazine (DNPH) derivatization followed by high-performance liquid chromatography (HPLC) is widely used. However, the method is often plagued by interference issues related to the ozone content in ambient air samples. Although the use of a potassium iodide (KI) scrubber circumvents these problems, the combination of a DNPH-coated silica cartridge and KI scrubber often performs poorly, particularly in high humidity. The KI in the scrubber becomes wet under these conditions, trapping the carbonyl compounds under investigation before they can reach the DNPH cartridge; this ultimately results in inaccurate readings. In this study, a new type of ozone scrubber consisting of a glass fiber filter coated with hydroquinone (HQF) was developed. The HQF scrubber was placed in front of the DNPH-coated silica cartridge, allowing airborne carbonyl compounds to pass unimpeded through the HQF section before being trapped by the DNPH-coated silica. The subsequent reaction of the trapped carbonyls with DNPH produced carbonyl 2,4-DNPhydrazone derivative that is used as the basis for the quantitative and qualitative analyses of ambient air samples. The hydroquinone in HQF reacts with ozone to form benzoquinone with an efficiency of more than 95% under wide relative humidity range (8 - 95%). The performance of our novel HQF scrubber was compared with those of potassium iodide (KI) and our previously developed trans-1,2-bis(2-pyridyl)ethylene (BPE)-coated silica scrubbers using ambient air samples, and the results showed that both HQF-DNPH and BPE-DNPH cartridges detected carbonyl compounds in the same concentration levels. The proposed method is superior to the KI-based and BPE-based technique for ozone removal because the HQF is very small and can be easily attached to any commercially available DNPH cartridge.

Iodide-adduct chemical ionization mass spectrometry (I-CIMS) is a widely used technique in the atmospheric chemistry community to detect oxygenated volatile organic compounds (OVOCs) in real time. In this work, we report the occurrence of secondary ion chemistry from interactions between a strong oxygen donor (such as O3 and peracids) and acidic OVOCs (such as carboxylic acids and organic hydroperoxides) in the ion-molecule reaction (IMR) region of I-CIMS. Such interactions can lead to acidic organic molecules (HA or HB) clustering with [IO]- (e.g., [HA + IO]-) and dimer adducts ([A + B + I]-), in addition to the well-known iodide clusters ([HA + I]-). This ion chemistry was probed using common chemical standards as well as the gas-phase oxidation products of α-pinene and isoprene in a flowtube reactor. The results show that secondary ion chemistry can lead to misinterpretations of molecular compositions and distributions of the gas-phase products and an overestimation of the elemental O/C ratio overall. Nevertheless, the varying degrees of signal change in response to the secondary ion chemistry might be a clue to inform OVOCs' functionalities. Specifically, in the α-pinene ozonolysis system, the extents of ion signal reduction in the presence of additional acids in the IMR suggest that C9H14O4 produced in the gas phase is a peracid, rather than the often-assumed pinic acid. Thus, we suggest that the potential application of the secondary ion chemistry to inform organic functionalities is promising, which could help better understand the molecular compositions of gas-phase OVOCs and the reaction mechanisms therein.

Acetaldehyde is one of the important VOC species of O3 precursors in the atmospheric environment. The influences of relative humidity (RH) and initial VOC/NOx ratio (RCN) on the formation of O3 are studied in smog chamber experiments, and the MCM v3.3.1 mechanism of acetaldehyde is modified based on the experimental results. In low-RH conditions (RH = 11.6%±1.1%), the O3 concentration at 6 h increases first and then decreases with the increase of RCN, and the RCN at the inflection point of O3 concentrations is 3.2. In high-RH experiments (RH = 78.8%±1.0%), variation of the O3 concentration at 6 h with RCN is similar to that in low-RH experiments, but the RCN at the inflection point is 2.8. RH has no significant effect on the O3 concentrations under low RCN ( 3). Compared with the experimental results, original MCM v3.3.1 greatly underestimates the O3 concentrations. Addition of both the photolysis process of peroxyacetyl nitrate and the photolysis process of HNO3 on the reactor surface into the original MCM can reduce the difference between the simulated O3 concentrations and the experimental results at 6 h from 24%−35% and 17%−49% to 6%−26% and 10%−42% under low- and high-RH conditions, respectively. The maximum incremental reactivity (MIR) of acetaldehyde simulated with the modified MCM is 4.0 ppb ppb−1 without considering the effect of other VOCs.

The chalcone derivatives of 20-oxo-lupanes have been synthesised and screened for some types of biological activity. Ozonolysis of lupanes afforded 20-oxo-derivatives with the following condensation using different aromatic aldehydes by Claisen‒Schmidt reaction to the target compounds. The

The component composition of plasma jets generated by a dielectric barrier discharge in helium and air at atmospheric pressure was studied by emission and absorption spectroscopy. The concentration of the main bactericidal component of the air plasma jet (ozone) was determined using both IR and UV absorption spectroscopy to increase the reliability of the measurements. A study of the effects of the plasma jets on Staphylococcus aureus bacteria established that the air jet had a better inactivating effect than the helium jet.

The paper presents the results of calculations of the dynamics of ozone destruction in the lower stratosphere, carried out taking into account the heterogeneous chemical reactions (HCRs) proceeding at a rate of w(–O3)HCRs, cm–3 s–1, with the participation of particles of the Junge layer (background aerosol). The dramatic decline in w(–O3)HCRs found in the calculations at altitudes less than 16 km in comparison with the rate of ozone loss calculated with the participation of gaseous chemical reactions (w(–O3)) indicates the inhibitory role of aerosol particles. This is due to the capture of N2O5 molecules from the air by aerosol particles. Their rapid runoff entails a sharp decrease in the concentrations of components of the NOx family in air, as well as a less pronounced decrease in the concentrations of components of the HOx, and Ox families involved in the destruction of ozone. At higher altitudes of 16 to 22 km, magnitude w(–O3)HCRs, in contrast, turns out to be slightly higher than w(–O3); and it affects the acceleration of the destruction process with the components of the HOx and ClOx families. The increased level of their concentrations and rates of reactions with ozone is due to the reduced content of the components of the NOx family in the air. This positive effect of the HCRs involving aerosol particles in w(–O3)HCRs practically degenerates, but at even higher altitudes. This is due to the decrease in the content of aerosol particles and the acceleration of the photodissociation of molecules N2O5(g) $$\xrightarrow{{h{{\nu }}}}$$ NO3(g) + NO2(g), which on the whole is accompanied by the suppression of the process of their capture by particles.

The article describes an efficient and straight forward method for the destruction of oxalate ions in the plutonium oxalate supernatant stream generated during the reprocessing of FBTR spent fuel, using ozone and electrolysis without any redox intermediates/catalyst at room temperature. The influencing parameters such as concentration of nitric acid, current density and temperature were studied. The destruction was achieved in 4 and 4.5 h, respectively using ozone and electrolysis. These methods have significant advantages due to the chemically benign nature of the oxalate destructed stream for all the downstream fuel cycle processes and the feasibility to automate these process steps in a radiochemical plant.

Transformations of aspen wood under the impact of ozone were investigated by FTIR spectroscopy and simultaneous thermal analysis combined with mass spectrometry (TG/MS) of noncondensable products of pyrolysis. The TG/DTG curves of lignocellulosic materials (LCM) obtained at various values of specific absorption of ozone were analyzed. Simulation of DTG curves with Gaussian components was carried out. It is shown that the content of hemicellulose (HC) and lignin (LG) decreases and the content of cellulose increases under the impact of ozone in wood. FTIR spectroscopy data confirm the destruction of aromatic structures of LG and indicate the formation of oxygen-containing products of biomass ozonation as the specific absorption of ozone increases. Based on the TG/MS analysis of the LCM and the simulation results, the range of ozone consumption corresponding to the predominant destruction of LG and HC, and the range of ozone reactions with the ozonation products of the LCM were established. Degradation of the cellulose structure was found at high ozone consumptions.