scholarly journals Development of a highly sensitive sampler for atmospheric monitoring of 8-H ambient ozone concentrations

2020 ◽  
Vol 25 (6) ◽  
pp. 938-945
Author(s):  
Gülnihal KARA
Keyword(s):  
Urban Areas ◽  
Sampling Rate ◽  
Composite Membranes ◽  
Ambient Air ◽  
Absorption Capacity ◽  
Passive Sampler ◽  
Passive Samplers ◽  
Winter Period ◽  
Highly Sensitive ◽  
Measurement Results

A new passive sampler reinforced with a composite membrane was developed to determine the 8-h ozone (O3) concentration in ambient air. The composite membrane's water absorption capacity and porosity values were found analyzing its surface morphology using Scanning Electron Microscopy (SEM).Ozone adsorption performance of this sampler was tested by a badge-type sampler and automated measurement results. The developed sampler gave results equivalent (R<sup>2</sup> = 0.85) to those of automated O3 monitors, and its experimental sampling rate was determined to be 55 cm<sup>3</sup>/min, approximately two times higher than the rate of the badge-type sampler. The detection limit obtained (5.3 μg/m<sup>3<.sup>, 8 h sampling) in the study was adequate for winter-period samplings where in the ozone concentration is low in urban and semi-urban areas. Multimedia sampling results revealed that the results of the developed passive sampler had a high repeatability (RSD < 20%). Passive samplers reinforced with composite membranes were tested by badge-type samplers performing simultaneous samplings in land conditions. Area sampling results indicated that badge-type samplers were not suitable for 8-h area samplings, but tube-type samplers could be used.

scholarly journals Development and Types of Passive Samplers for Monitoring Atmospheric NO2 and NH3 Concentrations

2001 ◽  
Vol 1 ◽  
pp. 513-529 ◽  
Author(s):  
Y.S. Tang ◽  
J.N. Cape ◽  
M.A. Sutton
Keyword(s):  
Rural Areas ◽  
Sampling Rate ◽  
Reference Method ◽  
Diffusion Path ◽  
Ambient Air ◽  
Passive Samplers ◽  
Diffusion Resistance ◽  
Positive Bias ◽  
Diffusion Tubes ◽  
Term Monitoring

Numerous passive samplers based on the ‘Palmes-tube’ have been developed for ambient air monitoring. In each case, the diffusion path length and/or crosssectional area are modified to achieve the desired sampling rate. ‘Tube-type’ samplers are low sensitivity samplers suitable for long-term monitoring, whereas the ‘badge-type’ samplers have faster sampling rates suited to short-term monitoring. In the U.K., diffusion tubes are widely used for monitoring nitrogen dioxide (NO2) and ammonia (NH3). The open-ended diffusion tubes are prone to positive bias caused by incursion of wind eddies, leading to a shortening of the diffusion path. By using a porous membrane at the inlet, wind incursion is prevented, but an additional diffusion resistance is imposed and it is necessary to calibrate the tubes against a reference method to obtain an effective sampling rate. For NO2 sampling, positive bias also arises from the reaction of NO with O3 within the sampler. The interference from the chemical reaction is severe close to NO sources, with errors up to 30% for curbside locations when using the ‘tubetype’ sampler. In rural areas, where NO concentrations are small relative to NO2, these errors are small. In some implementations, there is also a negative bias over long sampling periods caused by the degradation of trapped NO2. The low sampling rates of diffusion tubes make them too uncertain for use at background NH3 concentrations (<1 μg NH3 m-3) where they significantly overestimate concentrations. Badge-type samplers such as the ‘Willems badge’ samplers permit accurate sampling at low ambient NH3 concentrations, but suffer from saturation at high concentrations and sensitivity to wind speed. A passive sampler optimised for monthly measurements of NH3 is reported here, together with its application in the U.K. National Ammonia Monitoring Network.

scholarly journals BTEX and Nitrogen Oxides fume Assessments in Fuel Dispense Stations and Residential Areas

2021 ◽  
Author(s):  
Raslan A. Alenezi ◽  
Keyword(s):  
Nitrogen Oxides ◽  
Urban Areas ◽  
Ambient Air ◽  
Petroleum Products ◽  
Passive Samplers ◽  
Residential Areas ◽  
Potential Health ◽  
Rural And Urban Areas ◽  
Rural And Urban ◽  
The Government

Fuel vapors are released from storage tanks through vent pipes and from filling pump fuel dispensary stations. These petroleum-based by-products are introduced into ambient atmospheres and neighboring areas and may become a potential health risk. To investigate the quantity of benzene, toluene, ethylbenzene, and xylene (BTEX) and nitrogen oxides (NOx) concentrations as they are considered air pollutants and proven that they have negative health impacts on human. A selected fuel dispensing stations within Kuwaiti residential areas, passive samplers were deployed within selected fuel stations and also several residential areas for one week. Findings reveal that the concentration of BTEX at the fuel dispensing stations was significantly elevated than it was for the breathing pipe in residential areas. The concentration of benzene of 5.5 μg/m3 is slightly higher than the mean ambient concentrations in the rural and urban areas that 1 μg/m3 and 5–20 μg/m3, respectively. The levels are higher near such sources of benzene emission as fuel dispensing stations. As a result, the benzene close to the fuel stations is higher up to 70 μg/m3. Emissions escalate during weather change because of meteorological variables like temperature and wind direction influence dispersion of noxious compounds in the ambient air. With significant additions of harmful petroleum products into Kuwaiti air, a weary for respiratory and digestive implications may be paving the way to cause an ecological uproar. Hence, the government should use this baseline data and provide guidance to fuel dispensary stations for an improved method of fuel dispense, improvising fuel storing to minimise temperature change for fuel state preservation and, use of nozzles that increase dispensary speeds while minimising vapour production.

scholarly journals Development of Land Use Regression Model for Seasonal Variation of Nitrogen Dioxide (NO2) in Lahore, Pakistan

2021 ◽  
Vol 13 (9) ◽  
pp. 4933
Author(s):  
Saimar Pervez ◽  
Ryuta Maruyama ◽  
Ayesha Riaz ◽  
Satoshi Nakai
Keyword(s):  
Land Use ◽  
Air Pollution ◽  
Regression Model ◽  
Urban Areas ◽  
Industrial Development ◽  
Ambient Air ◽  
Ambient Air Pollution ◽  
Land Use Classification ◽  
Land Use Regression ◽  
Air Exposure

Ambient air pollution and its exposure has been a worldwide issue and can increase the possibility of health risks especially in urban areas of developing countries having the mixture of different air pollution sources. With the increase in population, industrial development and economic prosperity, air pollution is one of the biggest concerns in Pakistan after the occurrence of recent smog episodes. The purpose of this study was to develop a land use regression (LUR) model to provide a better understanding of air exposure and to depict the spatial patterns of air pollutants within the city. Land use regression model was developed for Lahore city, Pakistan using the average seasonal concentration of NO2 and considering 22 potential predictor variables including road network, land use classification and local specific variable. Adjusted explained variance of the LUR models was highest for post-monsoon (77%), followed by monsoon (71%) and was lowest for pre-monsoon (70%). This is the first study conducted in Pakistan to explore the applicability of LUR model and hence will offer the application in other cities. The results of this study would also provide help in promoting epidemiological research in future.

scholarly journals Regional Scale Impact of the COVID-19 Lockdown on Air Quality: Gaseous Pollutants in the Po Valley, Northern Italy

Atmosphere ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 264 ◽  
Author(s):  
Giovanni Lonati ◽  
Federico Riva
Keyword(s):  
Air Quality ◽  
Urban Areas ◽  
Regional Scale ◽  
High Volume ◽  
Ambient Air ◽  
Northern Italy ◽  
Traffic Emissions ◽  
Gaseous Pollutants ◽  
Po Valley ◽  
Concentration Levels

The impact of the reduced atmospheric emissions due to the COVID-19 lockdown on ambient air quality in the Po Valley of Northern Italy was assessed for gaseous pollutants (NO2, benzene, ammonia) based on data collected at the monitoring stations distributed all over the area. Concentration data for each month of the first semester of 2020 were compared with those of the previous six years, on monthly, daily, and hourly bases, so that pre, during, and post-lockdown conditions of air quality could be separately analyzed. The results show that, as in many other areas worldwide, the Po Valley experienced better air quality during 2020 spring months for NO2 and benzene. In agreement with the reductions of nitrogen oxides and benzene emissions from road traffic, estimated to be −35% compared to the regional average, the monthly mean concentration levels for 2020 showed reductions in the −40% to −35% range compared with the previous years, but with higher reductions, close to −50%, at high-volume-traffic sites in urban areas. Conversely, NH3 ambient concentration levels, almost entirely due the emissions of the agricultural sector, did not show any relevant change, even at high-volume-traffic sites in urban areas. These results point out the important role of traffic emissions in NO2 and benzene ambient levels in the Po Valley, and confirm that this region is a rather homogeneous air basin with urban area hot-spots, the contributions of which add up to a relatively high regional background concentration level. Additionally, the relatively slow response of the air quality levels to the sudden decrease of the emissions due to the lockdown shows that this region is characterized by a weak exchange of the air masses that favors both the build-up of atmospheric pollutants and the development of secondary formation processes. Thus, air quality control strategies should aim for structural interventions intended to reduce traffic emissions at the regional scale and not only in the largest urban areas.

Detection of direct-acting mutagens in ambient air: A comparison of two highly sensitive mutagenicity assays

1992 ◽  
Vol 20 (1) ◽  
pp. 19-28 ◽  
Author(s):  
Virginia S. Houk ◽  
Sumio Goto ◽  
Osamu Endo ◽  
Larry D. Claxton ◽  
Joellen Lewtas ◽  
...  
Keyword(s):  
Ambient Air ◽  
Highly Sensitive ◽  
Direct Acting

scholarly journals Experimental and artificial neural network approach for forecasting of traffic air pollution in urban areas: The case of Subotica

2010 ◽  
Vol 14 (suppl.) ◽  
pp. 79-87 ◽  
Author(s):  
Bogdana Vujic ◽  
Srdjan Vukmirovic ◽  
Goran Vujic ◽  
Nebojsa Jovicic ◽  
Gordana Jovicic ◽  
...  
Keyword(s):  
Air Pollution ◽  
Urban Areas ◽  
Meteorological Data ◽  
Model Development ◽  
Ambient Air ◽  
Ann Model ◽  
Statistical Parameters ◽  
Neural Network Approach ◽  
Starting Point ◽  
Artificial Neural

In the recent years, artificial neural networks (ANNs) have been used to predict the concentrations of various gaseous pollutants in ambient air, mainly to forecast mean daily particle concentrations. The data on traffic air pollution, irrespective of whether they are obtained by measuring or modelling, represent an important starting point for planning effective measures to improve air quality in urban areas. The aim of this study was to develop a mathematical model for predicting daily concentrations of air pollution caused by the traffic in urban areas. For the model development, experimental data have been collected for 10 months, covering all four seasons. The data about hourly concentration levels of suspended particles with aerodynamic diameter less than 10 ?m (PM10) and meteorological data (temperature, air humidity, speed and direction of wind), measured at the measuring station in the town of Subotica from June 2008 to March 2009, served as the basis for developing an ANN-based model for forecasting mean daily concentrations of PM10. The quality of the ANN model was assessed on the basis of the statistical parameters, such as RMSE, MAE, MAPE, and r.

scholarly journals THE INFLUENCE OF ABSORBENT SOLUTION ON THE EFFECTIVENESS OF PASSIVE DIFFUSIVE SAMPLERS

2010 ◽  
Vol 2 (5) ◽  
pp. 103-108 ◽  
Author(s):  
Vaida Šerevičienė ◽  
Vaida Valuntaitė ◽  
Dainius Paliulis
Keyword(s):  
Aqueous Solutions ◽  
Ambient Air ◽  
Gas Diffusion ◽  
Passive Samplers ◽  
Oxides Of Nitrogen ◽  
The European Union ◽  
Absorption Mechanism ◽  
True Meaning ◽  
Almost All ◽  
Absorbent Solution

The method of applying passive diffusive samplers for research on air quality is simple, easy enough and requires no electricity. The operating principle of almost all passive samplers is based on chemical reactions taking place on absorbent (impregnated filter or grid). The pollutant absorption mechanism is based on passive diffusion through the gas diffusion layer to absorbent. The diffusion process can be explained by first Fick’s law described as a free movement of gases from the ambient air to a passive sampler. This movement depends on pollutant gradient. The aim of this paper is to analyse the influence of an impregnating solution on the efficiency of diffusive samplers. The object of the study covers the triethanolamine (TEA) aqueous solutions of 5%, 10%, 20%, 30% and 50%. The results obtained showed that 30% and 50% aqueous solution gave 68% and 89% relative error making the true meaning of the oxides of nitrogen analyzer testimony. Data on the passive samplers impregnated with TEA aqueous solutions having concentrations of 5%, 10% and 20% are within definite 25% uncertainty established by the European Union Directives.

scholarly journals Emission from Uyo Main Refuse Dumpsite and Potential Impact on Health

2020 ◽  
pp. 8-13
Author(s):  
S. A. Nta ◽  
M. J. Ayotamuno ◽  
A. H. Igoni ◽  
R. N. Okparanma
Keyword(s):  
Air Quality ◽  
Quality Index ◽  
Ambient Air ◽  
Air Quality Index ◽  
Volatile Organic Carbon ◽  
Highly Sensitive ◽  
Volatile Organic ◽  
Landfill Emissions ◽  
Potential Impact ◽  
Pm2.5 And Pm10

This paper presents potential impact on health of emission from landfill site on Uyo village road, Uyo local government area of Akwa Ibom State, Nigeria. Three sampling points were assessed for particulate matter (PM2.5 and PM10), nitrogen dioxide (NO2), sulphur dioxide (SO2), carbon monoxide (CO), hydrogen sulphide H2S, ammonia (NH3), total volatile organic carbon (TVOC) and hydrogen cyanide (HCN) using highly sensitive digital portable meters. The data obtained were expressed in terms of an air quality index. Air quality index indicates that the ambient air can be described as unhealthy for sensitive groups for NO2, unhealthy for SO2 and PM2.5 and moderate for CO, respectively. H2S, NH3, TVOC, HCN, PM10 were not indicated in USEPA air quality standards. It recommended that stringent and proper landfill emissions management together with appropriate burning of wastes should be considered in the study area to ease the risks associated with these pollutants on public health.

scholarly journals Pressure Sensors: Cross‐Linked Gold Nanoparticle Composite Membranes as Highly Sensitive Pressure Sensors (Adv. Funct. Mater. 40/2020)

2020 ◽  
Vol 30 (40) ◽  
pp. 2070269
Author(s):  
Hendrik Schlicke ◽  
Svenja Kunze ◽  
Matthias Rebber ◽  
Norbert Schulz ◽  
Svenja Riekeberg ◽  
...  
Keyword(s):  
Gold Nanoparticle ◽  
Pressure Sensors ◽  
Composite Membranes ◽  
Highly Sensitive ◽  
Sensitive Pressure
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