Application of PEG based aqueous biphasic systems in extraction and separation of no-carrier-added 183Re from bulk tantalum

Production and separation of no-carrier-added 181−184Re radioisotopes from proton irradiated tungsten target

Cross sections for the production of 181−184Re isotopes from proton irradiated thin natWO3 target at 20.9, 17.9, 14.9, 11.9 and 8.8 MeV projectile energies have been measured. An acceptable agreement between experimentally obtained data and available literature reports was found. The produced no-carrier-added (NCA) Re radionuclides have been separated from bulk tungsten target by liquid-liquid extraction (LLX) using trioctyl amine (TOA) and di-(2-ethylhexyl)phosphoric acid (HDEHP) dissolved in cyclohexane. A clear separation has been observed at 0.1 M and 1 M TOA with 0.1 M HNO3 concentration. However, by using HDEHP NCA Re radionuclides could not be separated from bulk W target without its contamination.

Temperature and Concentration Dependence of Viscosity of Binary Mixtures of PEG-1000 + water

Viscosities of binary mixtures of polyethylene glycol-1000 (PEG-1000) and water were measured precisely in the temperature range 293.15–343.15 K at atmospheric pressure using a high precision viscometer. Viscosity data were used to calculate the activation energy of viscous flow. The activation energy was observed to increase with increase in the concentration of aqueous solutions of PEG which indicated that more energy is required to move the molecule inside the structure with increase in concentration. The measured data provided better understanding to explain the behaviour of macromolecules with respect to change in concentration and temperature. The results were discussed in the light of polymer-solvent interactions. At lower concentration range, the molecules exhibit weak interaction due to dominant repulsive force and at higher concentration the entanglement of polymer chain increases. In view of greater force of interaction between solute and solvent molecules forming hydrogen bonding, there will be an increase in interaction with temperature and concentration.

Green recovery of mercury from domestic and industrial waste

Recovery of mercury from effluents is fundamental for environmental preservation. A new, green method was developed for separation of mercury from effluent containing different metals. The extraction/separation of Hg(II) was studied using aqueous two-phase system (ATPS) comprising by polyethylene oxide (PEO1500) or triblock copolymers (L64 or L35), electrolyte (sodium citrate or sodium sulfate) and water in the presence or absence of chloride ions. The extraction behavior of the Hg(II) for the macromolecule-rich phase is affected by the following parameters: amount of added extractant, pH, and the nature of the electrolyte and macromolecule of the ATPS. The APTS of PEO1500+sodium citrate+H2O (pH 1.00 and 0.225 mol kg(-1) KCl) produced the highest Hg(II) %E=(92.3 ± 5.2)%. Under the same conditions, excellent separation factors (1.54×10(2)-3.21×10(10)) for recovery of mercury in the presence of co-existing metals were obtained. Efficient and selective extraction of Hg(II) from domestic and industrial synthetic effluents was achieved using this ATPS.

Aqueous biphasic separation of97Ru and95,96Tc from yttrium

An aqueous biphasic separation technique has been developed for the separation of⁹⁷Ru, a potential candidate radionuclide in nuclear medicine, from its target matrix, yttrium.