@conference{
author = "Vujasin, Radojka and Kumrić, Ksenija and Devečerski, Aleksandar and Omerašević, Mia and Egerić, Marija and Petrović, Đorđe Ž. and Matović, Ljiljana",
year = "2022",
abstract = "Dyes and pigments are used by many industries to color their products. In this study, we applied two different kinds of waste materials: used radioactive sources and carbon waste tire char (WTC) to study their simultaneous effect of irradiation/adsorption on dye degradation. Irradiation of methylene blue (MB) by high energy γ radiation derived from used radioactive sources in the presence of carbon based material made of waste tire granules caused enhanced decoloration of the MB. Delivered dose of radiations differ depending on the type of isotope. The best decoloration was achieved using 60Co isotope. Complete decoloration of 20 ml of MB solution having concentration of 100 mg dm-3 of WTC was achieved with delivered doze of only 60 Gy. Decoloration of 90% was achieved after only 20 min while complete decoloration of MB solution (100%) was obtained in the irradiated samples after only 100 min. Processes that use ionizing radiation (α, β and γ) for decoloration of dyes are characterized as advanced oxidation processes which normally utilize a strong oxidizing species to break down the macromolecules. High energy radiation in water medium can produce radiolysis of water i.e. formation of several active species such as H2, H2O2, H+, OH− , eaq− , •OH and •H which are responsible for chemical reactions in water solutions. The significance of this approach is, except using waste materials for achieving enhanced degradation of organic pollutants in the solution, avoiding the need for safe disposal and storage of waste radioactive sources. Also, less waste material is generated at the end of the simultaneous irradiation/sorption process compared to the pure sorption process. Surface composition of WTC, needed to elucidate the key mechanism of synergism of MB degradation, during the simultaneous adsorption/irradiation was obtained using FTIR and XPS technique. OH- ions, that originate from radiolysis of water induced by gamma irradiation and from the surface of WTC, play the crucial role in degradation of MB. MB molecule adsorbed at the surface of WTC is electronically reorganized and as a consequence degradated via the opening of the central aromatic ring containing both heteroatoms, S and N. OH- ions produced by water radiolysis also cause degradation of MB molecules in the solution.The synergetic effect is a result of the attack of • OH radicals on electrostatic reorganized MB molecule adsorbed on surface of carbon material. Opening of central aromatic ring of MB firstly appeared in cleavage of the double C-S+ =C bond and then cleavage of double N=C bond.",
publisher = "Belgrade : Vinča Institute of Nuclear Sciences - National Institute of thе Republic of Serbia, University of Belgrade, Belgrade : Serbian Society for Innovative Materials in Extreme Conditions (SIM-EXTREME)",
journal = "IMEC 2022 : 1st Intentational conference on innovativ materials in extreme conditions : Program and Book of abstracts",
title = "Water under extreme conditions: simultaneous gamma irradiation/carbon char adsorption resulted in improved methylene blue degradation",
pages = "56-56",
url = "https://hdl.handle.net/21.15107/rcub_vinar_12083"
}