Biennial Report 2005-2007 - Saha Institute of Nuclear Physics

Biophysical Sciences 229dynamic dissociation constant of a metal complexed with a bulky ligand with the help of dialysis.At the time of dialysis the polymer and the metal-polymer complex would remain inside the bagdue to the polymer’s huge molecular weight (40 kDa), and only the free ions would come out ofthe bag. It has been observed that Cr(III) / Cr(VI)-PVP complex is most stable at pH 7 andCr(III)-PVP complex is stronger than Cr(VI)-PVP complex at all pH values.Dalia Nayak, Anupam Banerjee†, Ayan Das†, Kingshuk Ghosh†, Susanta LahiriCSD6.1.10.5 Speciation dependent studies on removal of arsenic by iron-doped calciumalginate beadsThis work aims to study the differential attitude of Fe-doped calcium alginate (Fe-CA) beadstowards As(III) and As(V) compounds so that speciation dependent environmentally sustainablemethodologies can be developed for removal of arsenic. Throughout the experiment 76 As has beenused as precursor of stable arsenic. The affinity of As(V) towards the Fe-CA beads is greater thanthat of As(III). Removal efficiency of Fe-CA beads for As(V) increases with increasing number ofbeads and equilibration time. At pH 3, 30 Fe-CA beads remove As(V) completely from a solutioncontaining 20mg/kg As(V). The technique has been successfully applied to the arsenic contaminatedground water.Anupam Banerjee†, Dalia Nayak, Susanta LahiriCSD6.1.10.6 Separation of no-carrier-added 66,67 Ga produced in heavy ion induced cobalttarget using alginate biopolymersWe have developed a method of separation of no-carrier-added gallium radionuclides from cobalt byalginate biopolymer. Our method reduced requirement of chemicals including carcinogenic solvents.Heavy ion activation of natural cobalt foil with 84MeV 12 C results in the formation of no-carrieradded66,67 As radionuclides, along with their corresponding decay products, 66,67 Ge and 66,67 Gain the matrix. As arsenic and germanium radionuclides are short-lived, after a cooling period of10h only gallium radionuclides remain in the matrix. A complete separation has been achieved byadsorbing 66,67 Ga and lesser amount of bulk cobalt at pH 3 on Fe-doped calcium alginate beadsfollowed by desorbing cobalt from the beads with 0.4M NaNO 2 .Dalia Nayak, Anupam Banerjee†, Susanta LahiriCSD6.1.10.7 A new method of synthesis of iron doped calcium alginate beads and determinationof iron content by radiometric methodThe present study describes a new method of synthesis of an anionic biopolymer, iron doped calciumalginate beads (Fe-CA). The absorption of the anionic species depends mainly on the iron contentof the beads. Thus iron content in the Fe-CA beads has been determined employing radiometrictechnique using 59 Fe radiotracer. It has been found that Fe-CA beads contain 37.8 mg Fe/g of wetalginate beads in the proposed method, which is much higher than the earlier reported methods,