Keywords: high volume sampler, particle size, particle concentration, dry deposition flux, dry deposition velocity modelling, India, wind speed, atmospheric deposition, air pollution
Development of dry deposition velocity model for a typical medium level Indian city Karaikudi
In this study, day and night dry deposition samples were collected with Eagle II arrangement of dry deposition plates. Karaikudi, one of the medium level city in India has been the chosen as area of study. Sampling locations were classified as zone1, zone2 and zone3. Wind speed was also recorded during sampling. Particle size was determined by using X–ray diffractometer (XRD). Relation between particle size and dry deposition flux was also established. Different polynomials were tried to find out the best correlation between particle size and the dry deposition flux. Overall dry deposition velocity was calculated by taking slope of regression line between dry deposition flux and ambient concentration. Better correlation between wind speed and dry deposition flux was obtained during April '08. The resultant correlation coefficient (R) was found to be 0.8401 and 0.7295 for day and night respectively for a linear relationship. Using the collected data, dry deposition velocity model was developed by which correlation coefficient (R) between modelled dry deposition velocity and calculated dry deposition velocity was arrived as 0.9981. The present methodology would eliminate the enormous task of collecting the ambient dry deposition air sample and particle concentration and analyse the same in the laboratory.