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1.
Bull Environ Contam Toxicol ; 101(4): 494-500, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30132018

RESUMO

Lichens are very useful for monitoring of the radionuclide deposition because having a high efficiency capturing the radionuclides from the atmospheric fallout. In the present work, 210Po and 210Pb deposition in some lichen species were determined using an alpha spectrometer. Different lichens were collected around Demirci-Manisa and investigated their uses as biomonitor for 210Po and 210Pb deposition. The highest activity concentrations for 210Po and 210Pb were detected in Neofuscelia pulla (898 Bq kg-1 and 1207 Bq kg-1, respectively). The mean activities in the lichen species ranged from 164 to 584 Bq kg-1 for 210Po and from 175 to 671 Bq kg-1 for 210Pb. The activity ratios for 210Po/210Pb ranged from 0.75 to 1.57.


Assuntos
Poluentes Radioativos do Ar/análise , Radioisótopos de Chumbo/análise , Líquens/química , Polônio/análise , Monitoramento de Radiação , Turquia
2.
Appl Radiat Isot ; 192: 110606, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36549178

RESUMO

Since nuclear wastes are the most important wastes in terms of health and the environment, they are evaluated differently within nuclear reactors as well as in terms of their use in medical and industrial applications. In some cases, emergency intervention is necessary due to the amount of radioactivity or the physical and/or chemical conditions. . The purpose of this study is to investigate the adsorption properties of nano Ca3Y2B4O12 (CYBO) material synthesized by the sol-gel combustion method for the adsorption of Thorium (IV) from an aqueous medium. We tested how pH (3-8), the concentration of Th (IV) (25-125 mg/L), amount of adsorbent value (0.005-0.08 g) and temperature (20-60 °C), affect adsorption efficiency. The best possible combinations of these parameters were examined by Response Surface Methodology (RSM) and Artificial Neural Network (ANN). R2 values for RSM and ANN were 0.9964 and 0.9666, respectively. According to the models, the adsorption capacity under the optimum conditions determined for the RSM and ANN model was found to be 134.62 mg/g and 125.12 mg/g, respectively.


Assuntos
Tório , Poluentes Químicos da Água , Tório/química , Boratos , Adsorção , Redes Neurais de Computação , Íons , Concentração de Íons de Hidrogênio , Cinética
3.
Int J Biol Macromol ; 96: 459-465, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28013011

RESUMO

In this study, the removal of Reactive Black 5 (RB-5) by nano-ZnO/Chitosan composite beads (nano-ZnO/CT-CB) from aqueous solution was investigated. ZnO nanoparticles were prepared by the via the microwave-assisted combustion technique. And then nano-ZnO/Chitosan composite beads were prepared by polymerization in the presence of nano-ZnO and chitosan. Characterization of composite beads were conducted using SEM, TEM, FTIR, TGA and XRD. Several important parameters influencing the removal of RB 5 such as contact time, pH and temperature were investigated systematically by batch experiments. At optimum conditions of pH 4 and adsorbent concentration of 0.2g, dye removal efficiency was found 76%. Langmuir, Freundlich and Temkin adsorption models were used to describe adsorption isotherms and constants. The maximum adsorption capacity (qm) by Langmuir isotherm has been found to be 189.44mg/g. Isotherms have also been used to obtain the thermodynamic parameters such as free energy, enthalpy and entropy of adsorption. The positive value of the enthalpy change (32.7kJ/mol) indicated that the adsorption is an endothermic process. The obtained results showed that the tested adsorbents are efficient and alternate low-cost adsorbent for removal of dyes from aqueous media.


Assuntos
Quitosana/química , Nanocompostos/química , Naftalenossulfonatos/química , Naftalenossulfonatos/isolamento & purificação , Água/química , Óxido de Zinco/química , Adsorção , Corantes/química , Corantes/isolamento & purificação , Concentração de Íons de Hidrogênio , Cinética , Nanopartículas/química , Soluções , Temperatura , Poluentes Químicos da Água/química , Poluentes Químicos da Água/isolamento & purificação
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