Showing papers in "Journal of Geological Society of India in 2022"

AHP and GIS-based Delineation of Groundwater Potential of Papum Pare District of Arunachal Pradesh, India

Abstract: Water is crucial to human survival. Studies on surface water are well documented but precise knowledge of groundwater resources is difficult. Thus, accurate knowledge of groundwater resources could meet the necessities of water at present and in the long run. Application of the Analytic Hierarchy Process (AHP) and Geographical Information System (GIS) together with multi-criteria parameters has emerged as an efficient technique for delineation of groundwater potential in recent decades. However, no efforts to delineate the groundwater potential have been attempted in the study area till date. Hence, in this study, the groundwater potential of Papum Pare district of Arunachal Pradesh was delineated by combining AHP, overlay analysis, GIS, and ten thematic layers (geomorphology, geology, slope, lineament density, drainage density, rainfall, distance from the major river, topographic wetness index, soil texture, and land use/land cover). The results show about 64% of the area under poor groundwater potential. Moderate and good groundwater potential is found in 31% and 5% of the area. Map-removal and single-parameter sensitivity analyses revealed that the groundwater potential map is most sensitive to the annual average rainfall with a mean variation index of 1.05% and a weight of 19.07%. The flood/alluvial plains, Siwalik formations with sediments, and level to gentle slopes receiving high rainfall show good potential, and the dissected hills/valleys, metamorphic rock assemblages, steep slopes with low rainfall reveals poor groundwater potential. The overall accuracy of 81.25% with a Kappa coefficient of 0.72 explains good agreement between the reference data and the map. The estimated area under good groundwater potential appears too little concerning the increasing population and urbanization. Therefore, the state government in general and the water resources and planning department in particular need to formulate suitable strategies to combat the water scarcity scenario waiting ahead. The study suggests raising the use of surface water from nearby rivers to lessen the pressure on groundwater resources.

Partitioning of Rare Earth Elements (REEs) from Coal to Coal Fly Ash in Different Thermal Power Stations (TPSs) of India

Abstract: Rare earth elements (REEs) have been a topic of profound interest for several decades especially in the present age of electronic and digital revolution. India has the world’s richest beach sands with REEs, yet it imports some strategic REEs to fulfil its demand. It’s high time to explore alternative sources to meet its demand and coal ash from Thermal Power Stations (TPS) can be a very good alternative resource. In the present study, coal and coal fly ash (CFA) from seven Indian TPSs have been evaluated for estimation of REEs and variations in minerals compositions. Mineralogy of the samples is estimated using X-Ray diffraction (XRD) technique. Coal samples mostly consist of quartz and kaolinite however phase transformations of minerals occurred due to high temperature treatment during combustion. CFA mostly contains quartz and mullite. REEs have been determined by Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES) and considerable occurrence of any specific REE is not observed. Among the studied TPSs, Pr has the highest concentration among REEs in ash, reaching up to 63 ppm. The Outlook Coefficient (Cout) of REEs is in the range of 0.3–4.5 and 0.1–1.2 for coal and CFA respectively. In this research paper, Enrichment Coefficient (Δe) has been introduced to see the enrichment of REE in CFA with respect to the mother coal and a graph of Δe vs glassy phase has been plotted to observe the partitioning of REEs. Occurrence of Light REEs is more prominent than Heavy REEs.