Seasonal and Spatial Variations of Atmospheric Ammonia in the Urban and Suburban Environments of Seoul, Korea

Atmospheric ammonia is a significant pollutant throughout the year, necessitating standardized measurement and identification of emission factors. We performed a quantized evaluation of ammonia concentrations at various locations in and around Seoul, South Korea. The established testing methods of the Radiello Passive Sampler were used for ammonia sampling, and the method was validated using annular denuder sampling. Urban and suburban areas were studied to gain a deeper understanding of the factors responsible for ammonia pollution. This study aimed to establish the fluctuations in concentration over one year, by analyzing the seasonal and regional variation in ammonia concentration. Livestock and agricultural areas recorded the highest concentration of ammonia among all sites, with the highest concentration recorded in autumn. However, at most of the other studied sites, the highest and lowest ammonia concentrations were recorded during summer and winter, respectively. This study attempted to establish a correlation between ammonia concentration and temperature, as well as ammonia concentration and altitude.

Aerosol and Gas Phase Concentrations from an Adapted Annular Denuder System in a Broiler Housing Facility

HighlightsAn adapted annular denuder system (ADS) was implemented in a broiler facility to measure secondary aerosols.Results show that secondary aerosols were not always associated with ammonium or ammonia.Chloride aerosols were significant in comparison to other species and were present at consistent concentrations.This study concludes that the chloride source was the feed in the feeding pans.Abstract. Fine particulate matter (PM2.5) is present in animal housing facilities from both primary and secondary sources. Measuring secondary aerosols in harsh environments with high gas and particulate concentrations, such as poultry housing facilities, is an ongoing challenge. This study presents the results from the implementation of an adapted annular denuder system (ADS) used to measure secondary PM2.5 from inside a broiler facility in Ontario, Canada. Results from this work show that secondary aerosols formed the majority of total PM2.5 during the early portion of the growth cycle. It was further determined that the ion balance between ammonium and anions was not consistent, leading to the conclusion that a significant portion of the aerosol species are associated with a previously unidentified source that is not necessarily due to secondary reactions. Keywords: Ammonia, Annular denuder system, Particulate matter, Poultry, Secondary aerosols.

Evaluation of Alternative Annular Denuder Systems for the Collection of Fine Aerosol Particulate Matter

Due to the complex manner in which secondary inorganic aerosols (SIAs) form, a need exists to develop a methodology to measure PM2.5 emissions from agricultural operations to better understand the contribution of SIAs to the PM2.5 fraction. When sampling particulate matter (PM), annular denuder systems (ADS) are a United States Environmental Protection Agency (US EPA) approved system used to measure both gaseous and particulate components of aerosols. While collecting basic gases, such as ammonia, using nine denuders was feasibly demonstrated in poultry housing units but the ability of additional denuders to accurately collect the SIAs on the filters is yet to be demonstrated. An experiment was designed to assess particle deposition behaviors throughout three different ADS configurations. It was determined that the nine denuder configuration resulted in particles being impacted and retained, mainly in the U-bend junctions, prior to reaching the filters with only 87.2% of PM2.5 reaching the filter pack. The US EPA-prescribed ADS configuration had 99.4% of PM2.5 reaching the filters, indicating that there is an impact due to the U-Bend addition to the system. It was further demonstrated that having additional denuders in series with no U-Bend had no significant impact on PM2.5 deposition on the filters with 98.9% of PM2.5 being collected.

Monitoring of Air-Dispersed Formaldehyde and Carbonyl Compounds as Vapors and Adsorbed on Particulate Matter by Denuder-Filter Sampling and Gas Chromatographic Analysis

Carbonyl compounds (CCs) are products present both as vapors and as condensed species adsorbed on the carbonaceous particle matter dispersed in the air of urban areas, due to vehicular traffic and human activities. Chronic exposure to CCs is a potential health risk given the toxicity of these chemicals. The present study reports on the measurement of the concentrations of 14 CCs in air as vapors and 2.5 µm fraction PM by the ENVINT GAS08/16 gas/aerosol sampler, a serial sampler that uses annular denuder, as sampling device. The 14 CCs were derivatized during sampling prior to gas-chromatographic separation and multiple detection by mass spectrometry, nitrogen-phosphorus thermionic, electron capture detection. Outdoor air multiple samples were collected in four locations in the urban area of Florence. The results evidenced that formaldehyde, acetaldehyde, and acetone were the more abundant CCs in the studied areas. The data collected was discussed considering the particle to vapor ratio of each CC found. The CCs pollution picture obtained was tentatively related to the nature and intensity of the traffic transiting by the sampling sites. This approach allowed to determine 14 CCs in both concentrated and diluted samples and is proposed as a tool for investigating outdoor and indoor pollution.

Acid gases and aerosol measurements in the UK (1999–2015): regional distributions and trends

The UK Acid Gases and Aerosol Monitoring Network (AGANet) was established in 1999 (12 sites, increased to 30 sites from 2006), to provide long-term national monitoring of acid gases (HNO3, SO2, HCl) and aerosol components (NO3−, SO42−, Cl−, Na+, Ca2+, Mg2+). An extension of a low-cost denuder-filter pack system (DELTA) that is used to measure NH3 and NH4+ in the UK National Ammonia Monitoring Network (NAMN) provides additional monthly speciated measurements for the AGANet. A comparison of the monthly DELTA measurement with averaged daily results from an annular denuder system showed close agreement, while the sum of HNO3 and NO3− and the sum of NH3 and NH4+ from the DELTA are also consistent with previous filter pack determination of total inorganic nitrogen and total inorganic ammonium, respectively. With the exception of SO2 and SO42−, the AGANet provides for the first time the UK concentration fields for each of the other measured species. The ranges in site-annual mean concentrations (nmol m−3) in 2015 for the gases were: HNO3: 0.7–17; HCl: 2.4–21; SO2: 0.9–10, while those for aerosol were: NO3−: 6.3–53; Cl−: 22–89; SO42−: 2.2–11; Na+: 20–74; Ca2+:

The detection of nocturnal N₂O₅ as HNO₃ by alkali- and aqueous-denuder techniques

The almost total anthropogenic control of the nitrogen cycle has led to wide ranging trans-national and national efforts to quantify the effects of reactive nitrogen on the environment. A number of monitoring techniques have been developed for the measurement of nitric acid and subsequent estimation of nitrogen deposition within large networks and for process studies on shorter measurement campaigns. We discuss the likelihood that many of these techniques are sensitive to another important gas-phase component of oxidized nitrogen: dinitrogen pentoxide (N2O5). We present measurements using a MARGA wet annular denuder device alongside measurements of N2O5 with a discussion of evidence from the laboratory and the field which suggests that alkali- and aqueous-denuder measurements are sensitive to the sum of HNO3 + 2N2O5. Nocturnal data from these denuder devices should be treated with care before using HNO3 concentrations derived from these data. This is a systematic error which is highly dependent on ambient conditions and is likely to cause systematic misinterpretation of datasets in periods where N2O5 is significant proportion of NOy. It is also likely that deposition estimates of HNO3 via data obtained with these methods is compromised to greater and lesser extents depending on the season and environment of the sampling location.

The detection of nocturnal N₂O₅ as HNO₃ by alkali- and aqueous-denuder techniques

The almost total anthropogenic control of the nitrogen cycle has led to wide ranging trans-national and national efforts to quantify the effects of reactive nitrogen on the environment. A number of monitoring techniques have been developed for the measurement of nitric acid and subsequent estimation of nitrogen deposition within large networks and for process studies on shorter measurement campaigns. We discuss the likelihood that many of these techniques are sensitive to another important gas-phase component of oxidized nitrogen; dinitrogen pentoxide (N2O5). We present measurements using a MARGA wet annular denuder device alongside measurements of N2O5 with a discussion of evidence from the laboratory and the field which suggests that alkali- and aqueous-denuder measurements are sensitive to the sum of HNO3 + N2O5. Nocturnal data from these denuder devices should be treated with care before using HNO3 concentrations derived from these data. This is a systematic error which is highly dependent on ambient conditions and is likely to cause systematic misinterpretation of datasets in periods where N2O5 is significant proportion of NOy. It is also likely that deposition estimates of HNO3 via data obtained with these methods is compromised to greater or lesser extents depending on the season and environment of the sampling location.