Study of minerals and selected environmentally sensitive elements in Kapurdi lignites of Barmer Basin, Rajasthan, western India: implications to environment

The present study is an attempt to know the temporal and spatial distribution of geochemical components in the lignite deposit of Kapurdi, Barmer Basin (Rajasthan). Lignite samples have been subjected to proximate, ultimate and elemental analyses, and determination of mineral carbon (MINC%). Besides, various minerals and functional groups have been analyzed through X-ray diffraction (XRD) and Fourier transforms infrared spectroscopy (FTIR). Selected environmentally sensitive and potential hazardous elements like Cu, Cd, Zn, Ni, Cr, Pb, Mn, Al, Fe and Co are determined using atomic absorption spectrophotometer (AAS). To know the association of minerals with organic matter, scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) has also been carried out. The concentration of Co, Ni, Cd, Pb, Na, and K is high when compared with world average and is main concern for the environmental and health hazards. The elements like Fe, Ca, Mg, Zn, and Pb have shown increasing trend from top to bottom of the lignite seam with some fluctuations in the values in few bands whereas others do not follow a definite trend of variation along the seam profile.