Open AccessImmobilization of 60Co and 90Sr ions using red mud from aluminum industry
Author(s) -
A. Milenković,
Ivana Smičiklas,
Jelena Marković,
N. Vukelić
Publication year - 2014
Publication title -
nuclear technology and radiation protection
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.31
H-Index - 16
eISSN - 1452-8185
pISSN - 1451-3994
DOI - 10.2298/ntrp1401079m
Subject(s) - sorption , bauxite , red mud , chemistry , aqueous solution , desorption , distilled water , ion , langmuir adsorption model , nuclear chemistry , reaction rate constant , adsorption , inorganic chemistry , kinetics , chromatography , physics , organic chemistry , quantum mechanics
The removal of 60Co and 90Sr from the aqueous phase was tested using red mud - the fine grained residue from bauxite ore processing. This industrial waste represents a mixture of numerous minerals, mainly oxides and hydroxides of Fe, Al, Si, and Ti. Experiments were conducted as a function of contact time, pH, and pollutant concentrations. Kinetic data were well fitted with a pseudo-second order equation. The calculated rate constants and initial sorption rates indicated faster sorption of Sr2+ ions. Removal of both cations rapidly increased with the initial pH increase from 2.5 to 3.5. With the further increase of pH, Co2+ sorption was nearly constant (98%-100%), whereas Sr2+ removal remained at the same level to initial pH ~8 and gradually increased to 100% at pH 12. Equilibrium sorption data followed the Langmuir model, with the maximum sorption capacities of 0.52 mmol/g for Co2+ and 0.31 mmol/g for Sr2+. Sorbed cations exhibited high stability in distilled water. Desorption of Co2+ was also negligible in the presence of the competing Ca2+ cation, while 42%-25% of Sr2+ ions were desorbed depending on the previously sorbed amount. The results indicate that red mud is of potential significance as Co2+ and Sr2+ immobilization agent due to its high efficiency, abundance, and low-cost. [Projekat Ministarstva nauke Republike Srbije, br. 43009