4490043 Method of and apparatus for monitoring gaseous pollutants

1985 ◽  
Vol 19 (8) ◽  
pp. i
Author(s):  
John H Cramp ◽  
St Helens
Keyword(s):  
Gaseous Pollutants

Photo-catalytic degradation of gaseous pollutants in paper mills of southern China

TAPPI Journal ◽  
2018 ◽  
Vol 17 (03) ◽  
pp. 167-178 ◽  
Author(s):  
Xin Tong ◽  
Jiao Li ◽  
Jun Ma ◽  
Xiaoquan Chen ◽  
Wenhao Shen
Keyword(s):  
Degradation Rate ◽  
Southern China ◽  
Catalytic Degradation ◽  
Pulp And Paper ◽  
Gaseous Pollutants ◽  
Pulp And Paper Mills ◽  
Paper Mills ◽  
Initial Concentration ◽  
First Order ◽  
First Order Kinetics

Studies were undertaken to evaluate gaseous pollutants in workplace air within pulp and paper mills and to consider the effectiveness of photo-catalytic treatment of this air. Ambient air at 30 sampling sites in five pulp and paper mills of southern China were sampled and analyzed. The results revealed that formaldehyde and various benzene-based molecules were the main gaseous pollutants at these five mills. A photo-catalytic reactor system with titanium dioxide (TiO2) was developed and evaluated for degradation of formaldehyde, benzene and their mixtures. The experimental results demonstrated that both formaldehyde and benzene in their pure forms could be completely photo-catalytic degraded, though the degradation of benzene was much more difficult than that for formaldehyde. Study of the photo-catalytic degradation kinetics revealed that the degradation rate of formaldehyde increased with initial concentration fitting a first-order kinetics reaction. In contrast, the degradation rate of benzene had no relationship with initial concentration and degradation did not conform to first-order kinetics. The photo-catalytic degradation of formaldehyde-benzene mixtures indicated that formaldehyde behaved differently than when treated in its pure form. The degradation time was two times longer and the kinetics did not reflect a first-order reaction. The degradation of benzene was similar in both pure form and when mixed with formaldehyde.

scholarly journals Development of a Line Source Dispersion Model for Gaseous Pollutants by Incorporating Wind Shear near the Ground under Stable Atmospheric Conditions

2020 ◽  
Vol 4 (1) ◽  
pp. 17
Author(s):  
Saisantosh Vamshi Harsha Madiraju ◽  
Ashok Kumar
Keyword(s):  
Air Pollution ◽  
Urban Areas ◽  
Wind Shear ◽  
Dispersion Model ◽  
Near Field ◽  
Ground Level ◽  
Gaseous Pollutants ◽  
Air Pollution Control ◽  
Mobile Sources ◽  
Input Variables

Transportation sources are a major contributor to air pollution in urban areas. The role of air quality modeling is vital in the formulation of air pollution control and management strategies. Many models have appeared in the literature to estimate near-field ground level concentrations from mobile sources moving on a highway. However, current models do not account explicitly for the effect of wind shear (magnitude) near the ground while computing the ground level concentrations near highways from mobile sources. This study presents an analytical model based on the solution of the convective-diffusion equation by incorporating the wind shear near the ground for gaseous pollutants. The model input includes emission rate, wind speed, wind direction, turbulence, and terrain features. The dispersion coefficients are based on the near field parameterization. The sensitivity of the model to compute ground level concentrations for different inputs is presented for three different downwind distances. In general, the model shows Type III sensitivity (i.e., the errors in the input will show a corresponding change in the computed ground level concentrations) for most of the input variables. However, the model equations should be re-examined for three input variables (wind velocity at the reference height and two variables related to the vertical spread of the plume) to make sure that that the model is valid for computing ground level concentrations.

Analysis of improvement effect of PM2.5 and gaseous pollutants in Beijing based on self-organizing map network

2021 ◽  
Vol 70 ◽  
pp. 102827
Author(s):  
Shuang Liu ◽  
Atul Gautam ◽  
Xingchuan Yang ◽  
Jing Tao ◽  
Xinyu Wang ◽  
...  
Keyword(s):  
Gaseous Pollutants ◽  
Self Organizing Map ◽  
Improvement Effect ◽  
Self Organizing

An Automated Mobile Laboratory for Continuous Monitoring of Atmospheric Pollutants

1980 ◽  
Vol 194 (1) ◽  
pp. 357-364
Author(s):  
R. M. Harrison ◽  
H. A. McCartney
Keyword(s):  
Continuous Monitoring ◽  
Air Pollutant ◽  
Atmospheric Pollutants ◽  
Gaseous Pollutants ◽  
Mobile Laboratory ◽  
Digital Form ◽  
Pollutant Concentrations ◽  
Particulate Pollutants ◽  
Nitrate Fertilizer ◽  
Wet Chemical

The construction and operation of an automated mobile laboratory for continuous air pollutant monitoring are described. The gaseous pollutants sulphur dioxide, nitric oxide, nitrogen dioxide and ozone are monitored continuously, whilst particulate pollutants are collected for subsequent wet chemical analysis. Gaseous pollutant concentrations together with measurements of wind direction and speed and solar radiation are recorded continuously in both analogue and digital form. The problems inherent in siting and operating the mobile laboratory are discussed and the analysis of monitoring data is illustrated with reference to a recent survey carried out in the vicinity of an ammonium nitrate fertilizer works.

A model of the regional uptake of gaseous pollutants in the lung

1985 ◽  
Vol 79 (1) ◽  
pp. 11-27 ◽  
Author(s):  
Frederick J. Miller ◽  
John H. Overton ◽  
Richard H. Jaskot ◽  
Daniel B. Menzel
Keyword(s):  
Gaseous Pollutants

scholarly journals Uptake and fate of gaseous pollutants in leaves

1998 ◽  
Vol 139 (1) ◽  
pp. 221-223 ◽  
Author(s):  
J. N. CAPE
Keyword(s):  
Gaseous Pollutants

Microwave Torch Plasmas for Decomposition of Gaseous Pollutants

2004 ◽  
Vol 7 (1) ◽  
Author(s):  
Mariusz Jasiński ◽  
Jerzy Mizeraczyk ◽  
Zenon Zakrzewski
Keyword(s):  
Atmospheric Pressure ◽  
Energy Cost ◽  
Gas Flow ◽  
Coaxial Line ◽  
Low Energy ◽  
Gaseous Pollutants ◽  
Gas Flow Rate ◽  
Torch Discharge ◽  
Volatile Organic ◽  
Moderate Power

AbstractResults of the study of decomposition of volatile organic compounds (VOCs including Freons) in their mixtures with either synthetic air or nitrogen, and nitrogen oxides NOx in their mixtures with N2 or Ar in low (~ 100 W) and moderate-power (200-400 W) microwave torch plasmas at atmospheric pressure are presented. Three types of microwave torch discharge (MTD) generators, i.e. the low-power coaxial-line-based MID, the moderate-power waveguide-based coaxial-line MTD and the moderate-power waveguide-based MTD generators were used. The gas flow rate and microwave power (2.45 GHz) delivered to the discharge were in the range of 1÷3 l/min and 100÷ 400 W, respectively. Concentrations of the processed gaseous pollutants usually were from several up to several tens percent. The energy efficiency of decomposition of several gaseous pollutants reached 1000 g/kWh. It was found that the microwave torch plasmas fully decomposed the pollutants at relatively low energy cost. This suggests that the MTD plasma can be a useful tool for decomposition of highly-concentrated gaseous pollutants.

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.

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