C.T.Rajapaksha, T.K.Weerasinghe



Validating the Collecting Efficiency Factors of Wet Chemical Method for determination of Sulphur Dioxide and Nitrogen Dioxide in ambient air under Sri Lankan situation

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Air pollution has drawn worldwide concern as it has adverse effects on the health and welfare of all humans, on plants and on materials. Increase in level of Sulfur Dioxide (SO2) and Nitrogen Dioxide (NO2) has become a global threat and affects on the environment causing many issues to human health and quality of life. Thus, monitoring of these gases is a prime requirement to decide on the quality of ambient air as well as for formulation of air pollution management mechanisms. To monitor these two primary pollutants, high cost analytical methods are available. However, monitoring programs need to be cost-effective, sustainable and applicable to national and local priority needs and conditions. Therefore simplest technologies and procedures that are consistent with fulfilling overall monitoring objectives should be used. Even though the wet chemical methods (low cost) are available in the world wide, accuracy of these methods is depending on the local climatic conditions like temperature and humidity of atmosphere and the level of pollution in the region. Based on above factors, collection efficiency can be varied from region to region. Presently wet chemical methods are used to monitor SO2 and NO2 with use of collecting efficiency factors of gaseous pollutants in absorbing solution as in ASTM method. The main focus of this study was to get suitable collecting efficiency factors to Sri Lanka to measure SO2 and NO2 using wet chemical methods. Both SO2 and NO2 levels were determined by West and Gaeke method and Saltzman method as per the National Ambient Air Quality Standards. These values were also determined at the same location and same time by automated on-line analytical methods; Pulse Fluorescence method and Gas Phase Chemiluminescence method as per National regulations. Linear Regression Analysis was done to determine a suitable collecting efficiency factor in determining both NO2 and SO2. The collecting efficiency factors for both NO2 and SO2 for Sri Lanka was found out to be 0.72 and 0.99 according to this study instead of 0.82 and 1.00 used in ASTM methods respectively


Air quality, Chemiluminescence method, Collecting Efficiency, Wet chemical method, Pulse Fluorescence method


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Cite this paper

C.T. Rajapaksha, T.K. Weerasinghe. (2018) Validating the Collecting Efficiency Factors of Wet Chemical Method for determination of Sulphur Dioxide and Nitrogen Dioxide in ambient air under Sri Lankan situation. International Journal of Environmental Science, 3, 56-61


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