A5035553563- Radioactive element chemistry and processing
- Chemical Synthesis and Characterization
- Extraction and Separation Processes
- Nuclear Materials and Properties
- Radioactive contamination and transfer
- Analytical chemistry methods development
- Minerals Flotation and Separation Techniques
- Metal Extraction and Bioleaching
- Mineral Processing and Grinding
- Lanthanide and Transition Metal Complexes
- Chemical and Physical Properties in Aqueous Solutions
- Radioactivity and Radon Measurements
- Crystallization and Solubility Studies
- Analytical Chemistry and Chromatography
- Nuclear reactor physics and engineering
- Electrochemical Analysis and Applications
- Nuclear materials and radiation effects
- Chemical Thermodynamics and Molecular Structure
- Metallurgical Processes and Thermodynamics
- Molten salt chemistry and electrochemical processes
- Inorganic and Organometallic Chemistry
- Analytical Chemistry and Sensors
- Thermal and Kinetic Analysis
- Metallurgy and Material Forming
- Ionic liquids properties and applications
Amity University
2024
Bhabha Atomic Research Centre
2005-2015
University of Mumbai
2015
Florida State University
2006-2009
Bhabha Atomic Research Center Hospital
2009
National Metallurgical Laboratory
1996-2000
Abstract N,N,N′,N′‐Tetraoctyl diglycolamide (TODGA) has been evaluated as an extractant for the partitioning of minor actinides from simulated high level nuclear waste solutions. Acid uptake studies suggested that TODGA is more basic (KH: 4.1) compared to TRUEX and DIAMEX solvents viz. CMPO 2.0) DMDBTDMA 0.32), respectively. molecules display a tendency toward aggregation in n‐dodecane at lower acidities. Effect diluent on distribution behavior Am(III) was studied employing diluents...
Summary The effect of temperature on the extraction behaviour Am(III), Pu(IV) and U(VI) from nitric acid medium was studied employing N , ′, ′-tetraoctyl diglycolamide (TODGA) in n -dodecane. two-phase equilibrium constants (log K ′ ex ) were calculated compared with those other extractants proposed for actinide partitioning, viz. octyl-(phenyl)- -diisobutylcarbamoylmethyl phosphine oxide (CMPO) ′-dimethyl dibutyl tetradecyl malonamide (DMDBTDMA). Thermodynamic parameters, Δ G H S actinides...
Actinide partitioning studies with improved N,N,N',N'-tetraoctyl diglycolamide (TODGA) solvent (0.05 M TODGA + 5% iso-decanol in n-dodecane) has been explored order to achieve better decontamination from fission products. The distribution behavior of various metal ions, viz. Am, Pu, U, Eu, Sr, Pd, Cs, Tc, Fe, and Mo was investigated. Lower concentration as compared previously proposed 0.1 or 0.2 M) exhibited required extraction properties for actinide pressurized heavy water reactor high...
Abstract Counter-current mixer-settler studies for actinide partitioning were carried using N,N,N′,N′-tetra-2-ethylhexyl diglycolamide (T2EHDGA) as the extractant. The feed solution was Simulated High Level Waste of Pressurized Heavy Water Reactor (PHWR-SHLW) origin spiked with 241Am, 244Cm, 152Eu, 137Cs, 85,89Sr, 59Fe, 106Ru, 109Pd, 95Zr, and 99Mo tracers. organic stream 0.1 M T2EHDGA + 5% isodecanol in n-dodecane. Extraction, scrubbing, stripping experiments performed by maintaining an to...
Extraction behavior of four N,N-dialkylamides with varying alkyl substituents on the α carbon atom respect to carbonyl group, viz. di-(2-ethylhexyl)acetamide (D2EHAA), di-(2-ethylhexyl)propionamide (D2EHPRA), di-(2-ethylhexyl)isobutyramide (D2EHIBA), and di-(2-ethylhexyl)pivalamide (D2EHPVA) toward nitric acid, U(VI), Th(IV) has been investigated. The conditional acid uptake constant (K H) values for 1:1 species predominant in acidity range 0.5–3 M HNO3 are following order: D2EHAA...
The radiolytic stability of a promising extractant for actinide partitioning from high-level radioactive liquid waste, namely N,N,N',N'-tetraoctyl diglycolamide (TODGA) was investigated in the presence several phase modifiers, viz. N,N-dihexyloctanamide (DHOA), tri-n-butyl phosphate (TBP), 1-decanol, and iso-decanol dissolved n-dodecane. distribution ratio Am(III) decreased with increased radiation dose studied up to 1000 kGy. Nevertheless, all compositions extractants showed fairly high...
Straight chain amide N,N-dihexyloctanamide (DHOA) has been found to be a promising alternative extractant tri-n-butyl phosphate (TBP) for the reprocessing of irradiated uranium- and thorium-based fuels. Unlike TBP, DHOA displays preferential extraction Pu(IV) over U(VI) at higher acidities (≥3 M HNO3) poor lower acidities. Density functional theory (DFT) based calculations have carried out on structures relative binding energies with molecules. These suggest that differential hardness two...
The extraction behavior of di-2-ethylhexyl isobutyramide (D2EHIBA) in dodecane medium for U(VI), Th(IV), and fission products such as Zr, Ce, Eu, Cs, the structural material Fe, has been investigated over a wide range nitric acid concentrations. It observed that whereas D U varies from < 10−3 (pH 2.0) to 4.4 (6 M HNO3) with 1 ligand, corresponding Th values are 1.5 × 4 10−2. In presence 250 g/L Th, 8.6 2.2 HNO3). D2EHIBA found be promising extractant trace concentrations macro amounts Th. Fe...
The radiolytic stability of DHOA, a high molecular weight N,N‐dialkyl amide has been investigated to evaluate its performance under PUREX process conditions vis–a–vis TBP. Gas chromatographic studies revealed the presence caprylic acid, dihexylamine and dihexylketone in irradiated DHOA. Batch distribution Pu, U, fission products (144Ce, 103,106Ru, 137Cs) were carried out using samples 1.1 M DHOA TBP n‐dodecane, which showed significant retention as compared that even after successive...
Small-angle neutron scattering (SANS) studies were carried out to compare the aggregation behavior of 1.1 M solutions tributyl phosphate (TBP) and N,N-dihexyl octanamide (DHOA) dissolved in different deuterated diluents, viz., n-dodecane, chloroform, benzene, during extraction Th(IV) from nitric acid medium. The data was treated using Baxter sticky spheres model. third phase formed case DHOA displayed higher tendency compared that TBP. These have demonstrated nature diluents plays an...
The temperature effect on the extraction behaviour of U(VI) and Th(IV) from 3 M HNO employing 1 solutions N,N diallkyl amides with varying alkyl substituents C α atom viz. di(2-ethylhexyl)acetamide (D2EHAA), di(2-ethylhexyl)propionamide (D2EHPRA), di(2-ethylhexyl)isobutyramide (D2EHIBA) di(2-ethylhexyl)pivalamide (D2EHPVA) in n -dodecane has been investigated. These studies indicate that reactions are enthalpy stabilised while entropy factor counteracts extraction. An attempt made to...
Even though tri-n-butyl phosphate (TBP) has been the work horse for spent fuel reprocessing, some of its drawbacks are major concern. Based on batch extraction studies, our group at Radiochemistry Division, BARC proposed N,N-dihexyl octanamide (DHOA) as an alternative extractant to TBP reprocessing three component Advanced Heavy Water Reactor (AHWR) fuels. To validate data, twelve stage counter-current mixer settler runs were carried out a simulated AHWR feed [∼2 g/L U + ∼2 Pu 100 Th 0.03 M...
ABSTRACT Extraction behaviour of U(VI) and Th(IV) has been studied employing 0.5 M D2EHIBA (di(2-ethylhexyl)isobutyramide) in n-dodecane as a function nitric acid concentration. An improved separation U from Th could be achieved the presence fluoride ion. Use 1 Al(NO3)3 2 HNO3 suggested scrubbing solution. Various physico-chemical properties like density, viscosity, interfacial tension (IFT) limiting organic concentration (LOC) Th/U have measured to evaluate use process solvent. Degradation...