Environmental effect of acid mine drainage on pond ecosystem at Asansol coalfield area, Burdwan district, West Bengal

Acid mine drainage (AMD) is generated by formation of sulphuric acid, when sulphur containing materials such as pyrite undergoes weathering in the environment. Naturally occuring sulphur oxidizing bacteria also plays an important role in this process. The sulphuric acid so generated in this oxidation process is then able to dissolve metals like copper, leading in turn, to their release in the environment. The oxidation of pyrite is the single most prevalent cause of acid drainage. The equation can be summarized as follows:

In this context, four different samples designated as S₁,S₂,S₃ and S₄ were collected from four different sites, which includes Mangalpur pond of Ranigunj, Rajbandh of Barakar, Pochha Sayer of Samdi and Kuli Bandh of Chinakuri. Sampling was done both for chemical and bacteriological examination. In Sample–1, the water has a foul smell with high values of Ammoniacal Nitrogen, and Albuminoid Nitrogen, which suggests that the water has been highly contaminated with decomposable organic matter and Organic Nitrogen compounds both of plant and animal origin. The picture of sample 2 is more or less similar to that of sample-1, sample-3 and sample-4; however some parameter varies due to sewage water contamination. Moreover the results of sample-4 are almost same as other samples but its parameter varies due to mixing of different types of sewage from coalmine drainage system.