%0 Journal Article
%T Establishing the efficacy of the cleansing action of Tropical Evergreens:A Modeling Analysis of Asia's Largest Lignite Based Power Plant
%A J. R. Picardo
%A S. Ghosh
%J EnvironmentAsia
%D 2011
%I Thai Society of Higher Eduction Institutes on Environment
%X Developing nations of Asia will continue to rely on fossil fuels to meet their energy needs for years to come. In this context, mitigation of air pollution due to thermal power plant emissions assumes special significance. The Neyveli Lignite Corporation (NLC)- Asia's largest Lignite based Thermal Power Plant took a visionary step in this regard, four decades ago, via a massive afforestation program involving 17 million evergreen trees. These trees, now fully grown, play an important role in abating air pollution in the NLC town ship which is home to 128,133 people. This first study quantifies the cleansing action of these evergreens by employing a tailor-made atmospheric dispersion-deposition model which accounts for unique regional factors- the year round high solar insolation, high temperatures and the convective nature of the atmospheric boundary layer. We model the dispersion of SO2 emitted from multiple elevated stacks (typical source strengths are 300 g/s) and its deposition onto the evergreen canopy. Deposition is quantified in terms of the universal deposition velocity parameterization via inferential-resistance modelling of the transport pathways. Results indicate that considerable amount of pollution is deposited onto the canopy year round. In addition active cleansing of the atmosphere takes place over regions not directly in the path of SO2 emissions but nevertheless affected by residual pollution. This is relevant to large areas of NLC due to the wind pattern which involves a daily wind direction shift in the afternoon as well as several periods of calm. The present model has been coded to be made portable and can serve as a decision making tool in the screening, scoping and baseline analyses of Environmental Impact Assessment studies.
%K dry deposition
%K dispersion model
%K SO2 emissions
%K afforestation
%K deposition velocity
%U http://www.tshe.org/ea/pdf/vol4%20no2%20p1-8.pdf