ResearchPad - Nuclear Energy and Engineering https://www.researchpad.co Default RSS Feed en-us © 2020 Newgen KnowledgeWorks <![CDATA[Adsorption of 137Cs on titanate nanostructures]]> https://www.researchpad.co/product?articleinfo=5aebdb94463d7e32979fb7a5

Various types of sodium and potassium titanate nanostructures (nanotubes, nanofibers, nanoribbons, nanwires) were synthesized and characterized by X-ray diffraction, SEM and TEM, as well BET and BJH methods. Adsorption of radiotracer 137Cs+ ions from aqueous solutions on synthesized titanate nanostructures was investigated in batch technique as a function of contact time, concentration of sodium ions and pH of the solutions. It was found that among the studied nanostructures nanotubes shows the highest selectivity for 137Cs, which is related to a zeolitic character of Cs+ adsorption. The efficient adsorption of 137Cs was obtained in Na+ solutions with concentration below 10−2 M, at pH 7–9 and in contact time above 2 h. Moreover, nanotubes have the higher specific surface area than other nanostructures, which results in better availability of ion exchange groups and high ion exchange capacity. These properties of nanotubes indicate that they may be used for adsorption of 137Cs from various types of nuclear wastes.

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<![CDATA[Monitoring 60Co activity for the characterization of the sorption process of Co2+ ions in municipal activated sludge]]> https://www.researchpad.co/product?articleinfo=5aebdbd1463d7e32979fb7a6

In large volumes produced activated sludges from wastewater treatment plants (WWTPs) with low concentrations of heavy metals can be utilized as agricultural fertilizers and soil conditioners. Increased contents of toxic xenobiotics are limiting factors that affect the utilization of these heterogeneous wastes. The main aim of our paper was to show the utilization of dried activated sludge (DAS) from municipal WWTP as potential Co2+ ions sorbent i.e. for non-agricultural purposes. The radio indicator method by radionuclide 60Co and γ-spectrometry for characterization DAS sorption properties was used. DAS soluble and solid fractions were characterized by biochemical, ETAAS and CEC analysis. The sorption of Co2+ ions by DAS was rapid process and equilibrium was reached within 2 h. Sorption capacity of DAS (Q) increased with the initial concentration of CoCl2 in the range from 100 to 4,000 μmol l−1, reaching 20 and 160 μmol g−1. Obtained Q values were depent on pH value from 2.0 to 8.0. The maximum sorption capacity (Qmax) of DAS at pH 6 calculated from mathematical model of Langmuir adsorption isotherm was 175 ± 9 μmol g−1. FT-IR analyses showed the crucial role of carboxyl functional groups of DAS surfaces on cobalt uptake. For confirmation ion-exchange mechanism in sorption process of Co2+ ions by DAS scanning electron microscopy and EDX analysis were used.

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