The growth of population, indiscriminate establishment of industries, auto-mobiles etc., are some of the major causes for the atmospheric pollution, besides power shortage. There is a growing concern that pollution together with accelerated growth and development of nations may alter the climate due to the release of large amount of soot, carbon emission and other pollutants into the atmosphere in the form of ultra-fine dust particles which are suspended in the atmosphere called aerosols. They play an important role in the atmospheric processes favouring cloud formation due to large size aerosols and having adverse effects on health, depending on their size due to coagulation process. This book focuses on mathematical modelling of dispersion of aerosols in the presence/absence of electric field and first order chemical reaction using different dispersion models. The problems addressed here are representative of aerosol removal mechanisms. In order to keep the environmental problems mathematically tractable few simplifying assumptions have been made to the extent that they do not obscure the actual phenomena which was purportedly modelled in a restrictive yet representative sense.