International Journal of Environmental Sciences

Volume 7 Issue 4 2017- January 2017 Pages: 280- 289          Next >>                    

Study on speciation and effect of ionic strength on U Migration in Mineral-Water system

Author Information:

Sabyasachi Rout, Sarjan Singh, Ajay Kumar, P. M. Ravi, R. M. Tripathi -
Health Physics Division, Bhabha Atomic Research Centre, Mumbai, India-400085

ABSTRACT

An experiment was designed to study the speciation of uranium (U) at mineral-water interface and to study the effect of ionic strength (IS) of different salts on the migration of U from solid to liquid phase both in binary system (Mineral-water) and ternary system (Mineral-Water-Humic Acid). For the study ores bearing U-minerals differ in their host rocks were chosen and mineralogical study was carried out using XRD.  All the experiments were designed taking ore to water in the ratio 1g:10 mL. Speciation study of U in aqueous phase using speciation code MEDUSA revealed that (UO2)2 CO3(OH)3-, UO2(CO3)22-, UO2(CO3)34-, UO2CO3, UO2(OH)2, and UO2OH+ are the predominate species for both the systems. Study of speciation of U in terms of oxidation states indicates that about 5.4% of total U exist as U(VI) in ore A and reaming 94.6% in U(IV) state, whereas in Ore B about 9% of total U exist as U(VI) and reaming  91% in U(IV) state. Study of ionic strength versus desorption of U reveals that, there occurs an increase in U desorption from both the Ore A and B with increase in IS of the aqueous phase.  Ca2+ salts induces desorption more in comparisons to Na+ salt and among anions NO3- salts causes more desorption in comparison to Cl- salts. Study of ternary system (Ore-Water -Humic acid) revealed that, presence of humic acid (HA) accelerate the desorption in the experimental range of IS of all salts except in case of Ca-salts at higher ionic strength the U concentration reduces in aqueous phase of ternary system

Keywords: U, Ionic Strength, Speciation, Migration.

DOI:10.6088/ijes.7025

© 2017 Copyright by the authors, licensee Integrated Publishing Association.This is an open access article distributed under the Creative Commons Attribution License (3.0) which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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