Determination of Trace Elements Concentration in Mine Water - a Case Study of Jharia Coalfield

Jharia coalfield is one of the most important sources of coking coal in India. Coal mining activities in this coalfield have significantly caused mineralisation of surface and ground water; there-by adversely affecting it’s quality and utility. Several trace elements may be present in mine water released from various mining and processing operations. In this paper, an attempt has been made to assess the trace elements concentration in mine water in monsoon, winter and summer seasons in seven collieries of Jharia coalfield. The study areas comprised up three zones namely: non-fire, intermediate fire and fire zone depending on the level of fire activity in the selected coal mines. The trace elements that were selected for analysis were Pb, Zn, Cu, Fe, Mn, Co, Cd etc. For analysis of trace elements; samples were filtered using Whatman filter paper No.42. Then the samples were preserved after acidifying to pH <2 with 6 N conc. HNO3 in refrigerator till analysis in GBC-902 atomic absorption spectrophotometer. The results of the present investigations clearly reveal that mine waters of fire areas showed higher concentration levels of Pb, Zn, Cu, Fe, Mn vis-à-vis non-fire and intermediate fire areas. Ni, Cd and Co was found to be present in mine water samples of fire areas and absent in other areas. As, Se, Hg, and Cr were BDL in all the samples in the three seasons. In general, the trace elements concentrations were observed to be minimum in monsoon season and maximum in summer season. Trace elements index determined for mine water samples for different zones indicate that, mine water was ‘very slightly polluted’ in non-fire zone, ‘slightly polluted’ in intermediate fire zone and ‘moderately to highly polluted’ in the fire zone.