VOLATILE ORGANIC COMPOUNDS RELEASE FROM SELF-BURNING COAL WASTE PILES

Coal fires occurring all over the world have been the subject of several studies because of the associated environmental impacts, which include the emission of harmful gases and particulate matter into the atmosphere, mobilization and leaching of hazardous elements and formation of coal fires gas minerals, causing pollution of air, soils and sediments, surface and groundwater, and the effects on human health and biodiversity. Spontaneous and self-combustion of coal may occur during coal mining, storage, transportation and waste disposal. The characterization of self-burning coal waste material and the combustion by-products (gases and coal fire gas minerals) is essential to address the environmental and human health effects. The aim of the present research is to identify and quantify the volatile organic compounds (VOCs) emitted during the self-burning of Arroyo Galladas coal waste pile (Leon, Spain).

The results indicate that an extensive variety of VOCs are released to the atmosphere (some of them at great concentrations) including, among others, the BTEX compounds (benzene, toluene, ethylbenzene, and xylenes), which represent a serious environmental and human-health concern because are known or suspected to be toxic and human carcinogens. These results are consistent with those obtained from previous studies on VOCs released from Portuguese self-burning coal waste piles.

Aiming the remote, multi-point and continuous monitoring of gas emissions and combustion temperature in self-burning coal waste piles with optical fibre sensing technology, a scientific research project called “ECOAL – Ecological Management of coal waste piles in combustion”is under development. The project is composed by a consortium between Portuguese researchers from the Institute for Systems and Computer Engineering of Porto - INESC Porto and the Department of Geosciences, Environment and Spatial Planning, Faculty of Sciences, University of Porto, and partners from Spain and France. The results will allow the study of the dynamics and evolution scenarios of combustion process and the identification of hazards to the environment and human health.