Surface Interactions and Mechanisms Study on the Removal of Iodide from Water by Use of Natural Zeolite-Based Silver Nanocomposites
Vassilis J. Inglezakis,
Aliya Satayeva,
Almira Yagofarova,
Zhandos Tauanov,
Kulyash Meiramkulova,
Judit Farrando-Pérez,
Joseph C. Bear
Affiliations
Vassilis J. Inglezakis
Department of Chemical & Materials Engineering, School of Engineering and Digital Sciences, Nazarbayev University, Nur Sultan 010000, Kazakhstan
Aliya Satayeva
Department of Chemical & Materials Engineering, School of Engineering and Digital Sciences, Nazarbayev University, Nur Sultan 010000, Kazakhstan
Almira Yagofarova
Department of Chemical & Materials Engineering, School of Engineering and Digital Sciences, Nazarbayev University, Nur Sultan 010000, Kazakhstan
Zhandos Tauanov
Faculty of Chemistry and Chemical Technology, al-Farabi Kazakh National University, Almaty 050040, Kazakhstan
Kulyash Meiramkulova
Department of Environmental Engineering & Management, L.N.Gumilyov Eurasian National University, Nur Sultan 010000, Kazakhstan
Judit Farrando-Pérez
Laboratorio de Materiales Avanzados, Departamento de Química Inorgánica-Instituto Universitario de Materiales, Universidad de Alicante, 03690 Alicante, Spain
Joseph C. Bear
School of Life Science, Pharmacy & Chemistry, Kingston University, Penrhyn Road, Kingston upon Thames KT1 2EE, UK
In this work a natural zeolite was modified with silver following two different methods to derive Ag2O and Ag0 nanocomposites. The materials were fully characterized and the results showed that both materials were decorated with nanoparticles of size of 5–25 nm. The natural and modified zeolites were used for the removal of iodide from aqueous solutions of initial concentration of 30–1400 ppm. Natural zeolite showed no affinity for iodide while silver forms were very efficient reaching a capacity of up to 132 mg/g. Post-adsorption characterizations showed that AgI was formed on the surface of the modified zeolites and the amount of iodide removed was higher than expected based on the silver content. A combination of experimental data and characterizations indicate that the excess iodide is most probably related to negatively charged AgI colloids and Ag-I complexes forming in the solution as well as on the surface of the modified zeolites.
