Electrochemical based Gas Sensing for Ambient Air Quality Monitoring in Opencast Coal Mines

Air quality monitoring is mandatory in many industries like mining, refining and semiconductor industries owing to detrimental impact of air pollutants on the health of human beings, animals and the environment. There is a growing concern regarding the health impact of air pollutants on personal working in coal mines, both opencast and underground. Toxic gases in the ambient air can rapidly become a danger if not kept within safe permissible limits. The first step in maintaining air quality in coal mining areas is continuous monitoring of the atmospheric air. Toxic gases like carbon monoxide, nitric oxide, nitrogen dioxide and sulphur dioxide produced by various mining activities contribute to polluting the air. Several techniques are being used worldwide to sense the presence of various pollutant gases. This paper explores the various techniques for sensing of toxic gases in ambient air and sheds light into their pros and cons. It showcases a simple and cost-effective way of sensing toxic gases in areas near opencast mines by using electrochemical gas sensors. The paper also sheds light on the design of an ambient air quality monitoring instrument which uses electrochemical gas sensors for sensing the concertation of SO2, NO2, NO and CO at areas near opencast coal mines