Field Performance Evaluation of a newly Developed PM2.5 Sampler at IIT Kanpur.
ABSTRACT In order to meet the challenges of growing air pollution for a developing nation and to measure the ambient fine particles (PM2.5, particles having aerodynamic diameter less than 2.5 μm) on routine basis an air sampler was designed, developed and evaluated in the field. The impactor removes particles greater than 2.5 μm from the air stream via impacting them onto a vacuum grease substrate and finer particles get eventually collected on a backup filter. Various impactor nozzles with conical geometry were designed based on the published theoretical design equations. A detail parametric investigation was carried out which resulted in the optimum impactor nozzle design. For this exercise, a novel dry aerosol generator was employed in addition to the well known time-of-flight instrument, APS (Aerodynamic Particle Sizer, Model 3021, TSI Inc.). The average particle losses for the impactor nozzle as well as the sampler body were below 10% and the overall pressure drop (including a backup 47 mm filter) through the PM2.5 sampler was only 2 in. of H2O. This developed PM2.5 sampler operates at a flow rate of 15 LPM. Field performance of this sampler was evaluated through co-located sampling with a high volume PM2.5 reference sampler (HVS, GEM-BLI Model 2360, Tisch Environment Instrument) within the IIT Kanpur campus. The sampling period was 10 h long and it was carried out on six different days. The entire sets of filters were analyzed gravimetrically followed by their chemical analysis for elemental and anionic analyses. The particle mass, elemental, and anionic concentrations obtained with this newly developed PM2.5 sampler as well as those from the reference HVS sampler showed moderate to good correlation.
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ABSTRACT: The main objective of this atmospheric study was to determine the major sources of PM(1) (particles having aerodynamic diameter <1.0 μm) within and near the city of Kanpur, in the Indo-Gangetic Plain. Day and night, 10 h long each, filter-based aerosol samples were collected for 4 months (November 2009 to February 2010) throughout the winter season. These samples were subjected to gravimetric and quantitative chemical analyses for determining water-soluble ions (NH(4) (+), F(-), Cl(-), NO(3) (-), and SO(4) (2-)) using an ion chromatograph and trace elements using an inductively coupled plasma-optical emission spectrometer. The mean PM(1) mass concentrations were recorded as 114 ± 71 μg/m(3) (day) and 143 ± 86 μg/m(3) (night), respectively. A significantly higher diurnal contribution of ions (NH(4) (+), F(-), Cl(-), NO(3) (-), and SO(4) (2-)) in PM(1) mass was observed during the fog-affected days and nights throughout the winter season, for which the average values were recorded as 38.09 ± 13.39 % (day) and 34.98 ± 12.59 % (night), respectively, of the total PM(1) mass. This chemical dataset was then used in a source-receptor model, UNMIX, and the model results are described in detail. UNMIX provided a maximum number of five source factors, including crustal material, composite vehicle, secondary aerosol, coal combustion, and iron/steel production and metallurgical industries, as the dominant air pollution sources for this study.Environmental Science and Pollution Research 02/2013; · 2.62 Impact Factor