Hydrogeochemical characteristics of acid mine drainage and water pollution at Makum Coalfield,India |
| |
| Authors: | Sk Md Equeenuddin S Tripathy PK Sahoo MK Panigrahi |
| |
| Institution: | 1. Department of Mining Engineering, National Institute of Technology, Rourkela-769008, Orissa, India;2. Department of Geology & Geophysics, Indian Institute of Technology, Kharagpur-721302, West Bengal, India |
| |
| Abstract: | Acid mine drainage (AMD) is one of the severe environmental problems that coal mines are facing. Generation of AMD in the northeastern part of India due to the coal mining activities has long been reported. However detailed geochemical characterization of AMD and its impact on water quality of various creeks, river and groundwater in the area has never been reported. Coal and coal measure rocks in the study area show finely disseminated pyrite crystals. Secondary solid phases, resulted due to oxidation of pyrite, occur on the surface of coal, and are mainly consisting of hydrated sulphate complexes of Fe and Mg (copiapite group of minerals). The direct mine discharges are highly acidic (up to pH 2.3) to alkaline (up to pH 7.6) in nature with high concentration of SO42−. Acidic discharges are highly enriched with Fe, Al, Mn, Ni, Pb and Cd, while Cr, Cu, Zn and Co are below their maximum permissible limit in most mine discharges. Creeks that carrying the direct mine discharges are highly contaminated; whereas major rivers are not much impacted by AMD. Ground water close to the collieries and AMD affected creeks are highly contaminated by Mn, Fe and Pb. Through geochemical modeling, it is inferred that jarosite is stable at pH less than 2.5, schwertmannite at pH less than 4.5, ferrihydrite above 5.8 and goethite is stable over wide range of pH, from highly acidic to alkaline condition. |
| |
| Keywords: | Acid mine drainage Metal contamination Coal mines |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
