Physico-chemical studies in the removal of Sr(II) from aqueous solutions using activated sericite

Lalhmunsiama; Diwakar Tiwari; Seung-Mok Lee

doi:10.1016/j.jenvrad.2015.05.017

Physico-chemical studies in the removal of Sr(II) from aqueous solutions using activated sericite

J Environ Radioact. 2015 Sep:147:76-84. doi: 10.1016/j.jenvrad.2015.05.017. Epub 2015 Jun 2.

Authors

Lalhmunsiama¹, Diwakar Tiwari², Seung-Mok Lee³

Affiliations

¹ Department of Environmental Engineering, Catholic Kwandong University, 522 Naegok-dong, Gangneung, Gangwon-do 210-701, Republic of Korea.
² Department of Chemistry, School of Physical Sciences, Mizoram University, Aizawl 796004, India.
³ Department of Environmental Engineering, Catholic Kwandong University, 522 Naegok-dong, Gangneung, Gangwon-do 210-701, Republic of Korea. Electronic address: leesm@cku.ac.kr.

PMID: 26048059
DOI: 10.1016/j.jenvrad.2015.05.017

Abstract

Sericite, a mica based natural clay, was annealed at 800 °C for 4 h followed by acid activation using 3.0 mol/L of HCl at 100 °C in order to obtain activated sericite (AS). The activation of sericite causes a significant increase in specific surface area. Further, SEM images of the AS showed a disordered and heterogeneous surface structure with mesopores on its surface whereas the pristine sericite possessed a compact layered structure. The materials were further employed in the removal of Sr(II) from aqueous solutions in a batch reactor system. Removal of Sr(II) was studied as a function of pH, concentration of adsorbate, contact time, background electrolyte concentrations and dose of adsorbents using pristine sericite and AS. The removal of Sr(II) was favoured increasing the pH of the solution and the extent of Sr(II) removal was increased with increasing the sorbate concentration. Equilibrium sorption data obtained with pristine sericite were fitted well to Langmuir adsorption isotherm whereas the sorption data collected using AS better fitted to the Freundlich adsorption isotherm. The time dependence sorption data showed that the uptake of Sr(II) was very rapid and an apparent sorption equilibrium was achieved within 30 min and 60 min of contact for sericite and AS, respectively. The kinetic data were modelled to the pseudo-first order and pseudo-second order rate kinetics and sorption capacities as well as rate constants were evaluated. Increase in background electrolyte concentrations NaNO3 (0.001-0.1 mol/L) indicated that the presence of NaNO3 caused to decrease the percent removal of Sr(II) by sericite and AS. Furthermore, fixed-bed column reactor operations were performed to obtain the breakthrough data. The breakthrough data were fitted well to the non-linear Thomas equation. Therefore, the present study suggested that AS can be adequately applied for the removal of Sr(II) from the aquatic environment.

Keywords: Activated sericite; Breakthrough; Kinetic; Mesopore; Sr(II).

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adsorption
Aluminum Silicates / chemistry*
Kinetics
Strontium Radioisotopes / chemistry*
Water Pollutants, Radioactive / chemistry*
Water Purification / methods*

Substances

Aluminum Silicates
Strontium Radioisotopes
Water Pollutants, Radioactive
muscovite