Usha Narayanan

Selective separation of iron from uranium in quantitative determination of traces of uranium by alpha spectrometry in soil/sediment sample

During this work, controlled redox potential methodology was adopted for the complete separation of traces of uranium from the host matrix of mixed hydroxide of Iron. Precipitates of Fe(+2) and Fe(+3) along with other transuranic elements were obtained from acid leached solution of soil by raising the pH to 9 with 14N ammonia solution. The concentration of the uranium observed in the soil samples was 200-600 ppb, whereas in sediment samples, the concentration range was 61-400 ppb.

Interception/deposition of airborne85Sr,131I, and137Cs by spinach, radish and bean plants in a tropical region during rainfall

Interception/deposition factors for airborne85Sr,131I,137Cs following atmospheric releases under simulated raining condition have been evaluated in three different type of vegetables, i.e., beans (Phaseolus vulgaries), spinach (Spinacia oleracia) and radish (Raphamus sative). The rainfall rate in the chamber was 2 mm/h (48 mm/d). Activity was injected in the form of liquid aerosols having a size distribution of 2.33 μm (AMAD) with a GSD of 1.98 μm into the experimental chamber containing the vegetable plants having an arrangement to simulate rainfall. Samples were collected soon after the 30-minute rainfall period for the evaluation of interception/deposition factor (IF/DF) of85Sr,131I,137Cs on these plants. The maximum value of the interception/deposition factor was 6.04 m3·kg−1 which was observed for131I deposition to beans plant as a whole. Interception/deposition factor values were about 4 to 7 times higher compared to dry condition for the same of aerosols and inventories. The fraction of root activity to the activity of above soil parts has also been evaluated to determine the transfer of activity to the roots.