Ambient Air Quality Modelling Using Aermod and Particulate Matter Characterization in Opencast Mines

Abstract

Particulate Matter (dust) pollution is the most hazardous environmental issue associated with any opencast mining activity. Opencast extraction activities are major sources of air pollution in mining environment. The operations such as drilling, blasting, overburden/material handling and mineral processing generates large quantities of respirable particulate matter concentrations and are a potential source of air pollution. These airborne particulate matters are the main reason for the several severe health related issues such as Visibility disorder, Pneumoconiosis, neurological disorders etc. not only to the miners but to the people residing closer to mines. Therefore, the prediction of particulate matter concentration in and around the mine is essential to analyze the impact assessment of the mining activity over the surrounding environment. It is also necessary to identify the constituents of the particulate matter such that the severity of its impact can be analyzed at micro level.Considering the above situation the present work focuses on the monitoring of the different sources of particulate matter generation in Iron and Manganese mines using the gravimetric dust samplers (Envirotech APM 460 NL). The prediction of the fugitive dust concentration at different locations of mine and nearby areas is carried out using AERMOD software. The particulate matter characterization (PM10) of some Iron and Manganese ore Mines such as Kalta, Essel, Oraghat, Tantra and Sanindpur mines from Sundargarh district of Odisha has been carried out using Atomic Absorption Spectrophotometer to find the presence of major mineral compositions in it. Patmunda project which is an opencast manganese mine situated in Sundergarh district of Odisha, was chosen for the modelling purpose, where ambient air monitoring was conducted from September 2014 to November 2014 at an averaging period of 1 hour, 24 hour and monthly basis to derive the particulate matter generation behaviour in and around the mines. Different modelling options with different source pathways have been evaluated viz: Line source modelling, Volume source modelling and open pit. It is found that prescribed limits of NAAQS 2009. On the basis of these findings suitable mitigation and environmental plans can be devised for the sensitive areas.