Gaseous Emissions During the Coal Mining Activity and Neutralizing Capacity of Ammonium

摘要

This paper presents the simultaneous measurement of atmospheric concentration of gaseous NH_3, SO_2 and NO_2, and paniculate NH_4~+ released from the mining activities of coal-mine area, Tirap colliery, Margherita (Assam). Gas samples were collected by impinger method and were analyzed colori-metrically. The vapor-phase concentration of NH_3, SO_2, and NO_2 range between 4.7-40.03, 1.47-6.14, and 1.92-2.40 μg/m~3. The NH_4~+ concentration in PM_10 and PM_2.5 ranges between 0.02-0.07 and 0.008-0.03 μg/m~3, respectively. Moderately high concentrations of NH_3 and SO_2 on the first day were due to the coal-burning activity near the sampling site, while the low concentration of NO_2 is due to less vehicle density near the sampling point. All the observed concentrations are below than those reported for the urban areas and the prescribed limit fixed by National Ambient Air Quality Standard, India. Study indicates that ammonia is the major neutralizing agent for sulfate and nitrate ions present in the particulate matter during mining activities.