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Laxman Singh K.,Environment Protection Training and Research Institute | Sudhakar G.,Environment Protection Training and Research Institute | Swaminathan S.K.,Environment Protection Training and Research Institute | Muralidhar Rao C.,Atomic Minerals Directorate for Exploration and Research
Environment, Development and Sustainability

Uranium mill tailings are the crushed rock residues of the uranium extraction process from ores. The tailings effluent and tailings solids from the mill are discharged as slurry to a waste retention pond, called tailing pond. Natural radionuclides’ and trace metals are present in mine tailing/soil in varying concentrations, and some of these are found in elevated concentrations in uranium waste tailings. Uranium mine tailing ponds at Jaduguda and Turamdih receive waste from ores mined at the six mine stations at Jharkhand state, India. A study was undertaken to evaluate the potential of native plant species for the phytoremediation of these site. Three sampling stations were selected at Jaduguda (TP1, TP2, TP3) and Turamdih and at the downstream of effluent treatment plant. pH, electrical conductivity, metals (12-Al, V, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Cd, Pb) and radionuclides’ (3-Co, Sr and U) were analyzed using inductively coupled plasma mass spectrophotometry. From the analysis, four elements—Al, Mn, Fe and U—were found to be much higher in concentration in water with range (mg/kg) of 0.02–2.38, 0.30–31.67, 0.00–0.75 and 0.03–5.50, respectively, and 10 elements—of U, Mn, Al, V, Fe, Ni, Cu, Zn, Co and Se—were found to be higher in concentrations in soils with range (mg/kg) of 22–99, 1,072–8,065, 14,053–21,213, 66–139, 15,163–44,640, 149–240, 135–350, 89–191, 34–140 and 12–122, respectively. Among them, U and Mn were identified as predominant contaminants. Out of all the native plants, 21 species were screened for phytoaccumulation and transfer factor study. P. digitalis (for Al, V, Ni and Co), E. ferox (for Mn and Cu), A. indica (for Fe), B. vitisidae (for Zn), P. hydropiper (for Se) and S. spantanium (for U) were identified for hyper-accumulation, and A. indica (for Al, Co, Se and U), C. bunplandianus (for Mn, Fe, Ni and Cu), E. ferox (for V) and C. procera (for Zn) were listed for non-accumulation of respective contaminant. Besides this, taking consideration of the parameters such as shallow-rooted plant species, easy to adapt, growth, harvest and biomass production and simultaneous accumulation of multiple contaminants, following plants were found to be candidate species for phytoremediation of tailing ponds of uranium mines: For hyper-accumulation: P. vittata (can accumulate Al, V, Ni, Co, Se and U simultaneously) followed by P. digitalis, C. compressus and S. spantanium. For non-accumulation: C. bunplandianus (can non-accumulate Al, Mn, Fe, Ni, Co, Cu, Zn, Se and U simultaneously) followed by B. moneri, C. procera and A. indica. © 2014, Springer Science+Business Media Dordrecht. Source

Tripathy S.,Indian Institute of Technology Bhubaneswar | Bhattacharyya P.,Indian Statistical Institute | Mohapatra R.,Minnesota State University, Mankato | Som A.,Atomic Minerals Directorate for Exploration and Research | Chowdhury D.,Indian Institute of Technology Kharagpur
Ecological Engineering

The ratios of microbial parameters/organic carbon indicated that inhibition of microbial growth. The study was carried out on an municipal solid waste dumping site, more than hundred year old, located on the outskirts of Kolkata metropolitan city in India to determine the concentrations of different forms of selected metals (Zn, Cu, Pb, Cr, and Ni), their effect on microbial ecophysiological parameters (microbial biomass, microbial metabolic quotient, microbial respiration quotient), fluorescein diacetate hydrolyzing activity and enzyme activities in solid waste amended soils. A sequential extraction technique was used to quantify water soluble, exchangeable, carbonate bound, Fe/Mn oxide bound, organic bound, and residual fractions of metals. Metal concentrations in the two most labile fractions (i.e. water soluble and exchangeable fractions) were generally low. The concentrations of different forms of metals, microbial ecophysiological parameters and enzyme activities were found to be significantly higher in solid waste amended soils compared to the normal background soil around the study area. Significant positive correlations were observed between the microbial parameters and organic carbon content of the waste amended soil. The contents of microbial biomass C, fluorescein diacetate and enzyme activities did not necessarily decrease with increasing heavy metal content, reflecting the importance of other environmental factors, e.g. differences in organic C content. The ratios of different microbial parameters with organic C were significantly negatively correlated with metal concentrations while inhibition increased with increased bioavailability of metals. Although the waste amended soils had significantly higher microbial biomass and activities than the background soil, due to higher organic matter content, the ratios of microbial parameters/organic carbon indicated that inhibition of microbial growth and activities had occurred due to metal stress. This indicates that the use of municipal solid wastes in agriculture would lead to destruction of soil quality in the long run. © 2014 Elsevier B.V.. Source

Kukreti B.M.,Bhabha Atomic Research Center | Kumar P.,AMD Inc | Sharma G.K.,Atomic Minerals Directorate for Exploration and Research
Applied Radiation and Isotopes

Exploratory drilling was undertaken in the Lostoin block, West Khasi Hills district of Meghalaya based on the geological extension to the major uranium deposit in the basin. Gamma ray logging of drilled boreholes shows considerable subsurface mineralization in the block. However, environmental and exploration related challenges such as climatic, logistic, limited core drilling and poor core recovery etc. in the block severely restricted the study of uranium exploration related index parameters for the block with a high degree confidence. The present study examines these exploration related challenges and develops an integrated approach using representative sampling of reconnoitory boreholes in the block. Experimental findings validate a similar geochemically coherent nature of radio elements (K, Ra and Th) in the Lostoin block uranium hosting environment with respect to the known block of Mahadek basin and uranium enrichment is confirmed by the lower U to Th correlation index (0.268) of hosting environment.A mineralized zone investigation in the block shows parent (refers to the actual parent uranium concentration at a location and not a secondary concentration such as the daughter elements which produce the signal from a total gamma ray measurement) favoring uranium mineralization. The confidence parameters generated under the present study have implications for the assessment of the inferred category of uranium ore in the block and setting up a road map for the systematic exploration of large uranium potential occurring over extended areas in the basin amid prevailing environmental and exploratory impediments. © 2015 Elsevier Ltd. Source

Maithani P.B.,Atomic Minerals Directorate for Exploration and Research | Srinivasan S.,Atomic Minerals Directorate for Exploration and Research
Energy Procedia

Felsic volcanics constitute a primary source of uranium for forming an economic deposit. All over the world, volcanic rocks have not received due attention they deserve in uranium exploration. The volcanogenic deposits have been grouped with "other deposits", as they constitute a meager <0.5% of world uranium resources. Exploration inputs in the western world have identified a number of uranium deposits associated with volcanic rocks. The uranium resources contributed by volcanic type deposits all over the world stand at 3, 62, 000 te U3O8 (IAEA 2008 Compilation). The significance of acid volcanic rocks as a potential uranium source lies in the readily leachable form of their uranium content. A detailed study carried out in Australia to understand the spatial and temporal relationsh ip between the uranium deposits and the unmineralized, uranium enriched rocks from across the continent clearly indicated the role of the acidic volcanics as a potential provenance. Among the acid volcanics, rhyolites form an ideal source followed by welde d tuffs, ignimbrites, etc. The alkali or topaz rhyolite is ideal for its enrichment in many lithophile elements including uranium, which are amenable to subsequent leaching by meteoric water. In India the uranium exploration activities in the early 50s till the 90s were mainly confined to the Singhbhum Shear Zones, the Himalayas, Meghalaya plateau, parts of Central India and the geological environs of the Dharwar Craton. The granitic rocks, especially the peraluminous biotite - granite was always considered as a potential source for uranium and the geological environs closer to these granites always remained the first order targets. A number of small to medium size uranium deposits have been identified in Singhbhum Shear Zone, parts of Cuddappah, Bhima Basins and in Meghalaya. Now since the significance of the volcanic rocks, especially the felsic volcanics as a potential source of uranium has been clearly understood, it is imperative to reorient our exploration strategy to tap the potential of these volcanic rocks. The Malani Magmatic Province (MMP) in the northwestern part is the largest suite of an-orogenic acid volcanics in India occupying an area of 50000 sqkm. The Proterozoic Basins of India are replete with volcanic activity, mainly acid volcanism. In the southern and Central India, Dharwar and parts of Central Indian Craton also witnessed significant acidic igneous activities. The Cuddapah and the Vindhyan Basins have also recorded extensive acidic volcanic activity in the Papaghni, Chitrvati, Nallamalai Groups and Semri and Kaimur Groups respectively. In view of this the Proterozoic Basins mentioned above and the geological environs adjacent to the MMP deserve a re -look to have a proper assessment of their uranium potential, using integrated exploration inputs. © 2011 Published by Elsevie Ltd. Source

Basu H.,Atomic Minerals Directorate for Exploration and Research | Sastry R.S.,Osmania University | Achar K.K.,Atomic Minerals Directorate for Exploration and Research | Umamaheswar K.,Atomic Minerals Directorate for Exploration and Research | Parihar P.S.,Atomic Minerals Directorate for Exploration and Research
Precambrian Research

An analysis of facies was done to understand the depositional environment and the palaeoclimate of the sedimentary succession from the lower part of the Palaeoproterozoic (~2.0. Ga) Gulcheru Formation exposed along the southwestern margin of the Cuddapah Basin. Twelve distinct sedimentary facies were identified and grouped into three main facies associations - wadi fan, ephemeral fluvial and aeolian. Identification of the fluvial and the aeolian facies allowed a more elaborate interpretation of the depositional environment and its palaeoclimate. Facies characteristics indicated that the sediments in the beginning were deposited in a dominantly aeolian realm, under warm and semiarid climatic condition. Translatent strata, pin stripe lamination, zibars, high-index granule ripples, sand sheet deposits, grainflow cross-strata and grainfall laminae, asymptotically down-lapping cross-strata often with erosional lower bounding surface and massive sand-bodies with bimodal fabric, the unambiguous evidences of aeolian depositional regime led to this conclusion. However, the aeolian regime was often punctuated temporarily by fluvial input from ephemeral streams during sudden rainstorm. Depending upon the size, character and availability of sediments, relief difference and the sediment/water ratio cohesionless debris flow, hyperconcentrated flood flow and sheetflood deposits were formed near the basin margin, whereas, coarse-load braided channel deposits were laid further inside the basin. Ephemeral lakes/ponds were formed due to stagnation of floodwater in normally dry interdune lows. Overbank-interdune sediments were deposited in those ephemeral lakes/ponds. Amongst the aeolian facies, translatent strata and sand sheet dominate in the west, whereas, massive beds and dunes with well-developed slipfaces dominate in the eastern part. The spatial distribution of the aeolian bedforms suggests development of erg apron to the west and dune field (erg) to the east. The aeolian sediments identified in the Gulcheru Formation may be considered to be amongst the oldest Palaeoproterozoic aeolian sediments of the world. © 2014 Elsevier B.V. Source

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