A radioactively durable melamine-styrene based polymer: Highly efficient removal of 90Sr

Erhan Karabayir; Abdil Ozdemir; B Filiz Senkal; Omer S Taskin

doi:10.1016/j.apradiso.2019.04.024

A radioactively durable melamine-styrene based polymer: Highly efficient removal of ⁹⁰Sr

Appl Radiat Isot. 2019 Jul:149:96-103. doi: 10.1016/j.apradiso.2019.04.024. Epub 2019 Apr 24.

Authors

Erhan Karabayir¹, Abdil Ozdemir², B Filiz Senkal³, Omer S Taskin⁴

Affiliations

¹ Technology Development Department, TR34303, K. Cekmece, Istanbul, Turkey; Department of Chemistry, Sakarya University, TR54187, Serdivan, Sakarya, Turkey. Electronic address: erhan.karabayir@taek.gov.tr.
² Department of Chemistry, Sakarya University, TR54187, Serdivan, Sakarya, Turkey.
³ Istanbul Technical University, Faculty of Science and Letters, Department of Chemistry, Maslak, 34469, Istanbul, Turkey.
⁴ Istanbul University, Institute of Marine Science and Management, Department of Chemical Oceanography, Fatih, 34134, Istanbul, Turkey.

PMID: 31048202
DOI: 10.1016/j.apradiso.2019.04.024

Abstract

Removal of strontium has a vital importance for radioactive waste management due to its long half-life. In this context, melamine-styrene based polymer (MSBP) was synthesized and characterized by different spectrophotometric methods. Sr²⁺ ions were removed from the solution using MSBP sorbent. In this respect, adsorption of Sr²⁺ onto melamine-based polymer was studied as a part of pH, amount of adsorbent, initial Sr²⁺ concentration, contact time, temperature and particle size. Also, adsorption rate of radioactive strontium was investigated by using LSC (Liquid Scintillation Counter). The adsorption data were fitted to Langmuir, Freundlich and Dubinin-Radushkevich (D-R) isotherm models. MSBP sorbent reached maximum adsorption capacity for Sr²⁺ as 142.9 mg.g^-1. Thermodynamic parameters such as free energy (ΔG⁰), entropy (ΔS⁰) and enthalpy (ΔH⁰) of Sr²⁺ adsorption on MSBP were examined at five different temperatures of 293 K, 303 K, 313 K, 323 K and 333 K. 0 < ΔH⁰ values indicated that sorption mechanism presented endothermic feature. 0 > ΔG⁰ and 0 < ΔS⁰ revealed that Sr²⁺ adsorption on MSBP occurred spontaneously and irreversible, respectively. Pseudo first and second orders were investigated as a part of kinetic parameters and seen that pseudo second order was much more convenient for adsorption of Sr²⁺ onto MSBP.

Keywords: Adsorption; Kinetic and thermodynamic parameters; Liquid radioactive waste; Polymeric adsorbent; Strontium.