Search Results

You are looking at 1 - 2 of 2 items for

  • Author or Editor: S. Abidi x
  • Refine by Access: All Content x
Clear All Modify Search

Abstract  

The measurements of natural radioactivity due to thorium isotopes have been carried out in estuarine sediments of Mandovi river (Goa). The geochemical behaviour of these sediments has been studied by leaching the samples with 5 % ethylenediaminetetraacetic acid at pH 3.0 in order to investigate the processes occurring on the surface of the sediment particles and the distribution of natural thorium in estuarine sediments. The228Th/232Th activity ratios have been found to be in the range of 2.00 to 2.12. This anomaly between232Th and228Th has been attributed to the preferential leaching of228Ra by water flowing over these sediments. The activities of228Ra on the surface labile layers of the sediments have also been determined. The230Th/232Th activity ratios have been found to be in the range of 0.94 to 1.04. These ratios are mainly dependent on the precipitation action of230Th on adjacent sediments.

Restricted access

Abstract  

The surface leaching of the labile component of uranium has been carried out in estuarine sediments of Zuari river in Goa. The measurements of alpha activities of238U,235U and234U in the leachates indicated a remarkable anomaly between the activities of238U and234U. The activity ratios of234U/238U in these leachates have been found to be in the range of 1.10 to 1.14. However, the activity ratios of235U/238U have been found to be 0.045 which is close to that in natural uranium. It has also been observed that the anomaly between238U and234U exists only on the surface organic layers of the backwater sediments of the Zuari river.

Restricted access