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SM ISO690:2012 NASTAS, Raisa, CEBAN (GÎNSARI), Irina, LUPASCU, Tudor. Vegetal active carbons for adsorption of toxic metal ions. In: Achievements and perspectives of modern chemistry, 9-11 octombrie 2019, Chişinău. Chisinau, Republic of Moldova: Tipografia Academiei de Ştiinţe a Moldovei, 2019, p. 183. ISBN 978-9975-62-428-2. |
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Achievements and perspectives of modern chemistry 2019 | ||||||
Conferința "International Conference "Achievements and perspectives of modern chemistry"" Chişinău, Moldova, 9-11 octombrie 2019 | ||||||
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Pag. 183-183 | ||||||
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The presence of heavy metals in the environment is a major concern due to their toxicity to many life forms. With the increase in the number of nuclear power reactors, the radioactive pollution of water and soil is growing. Heavy and radioactive metals (such as Pb, Cd, As, Cs, Sr, Co, Hg etc.) are persistent pollutants with potential hazards, which are characterized with a high toxicity, difficult biodegradation, and are easily accumulated in organisms [1]. Adsorption on active carbons is one of the procedures used for binding of toxic metals [2,3]. In this study, activated carbons of local origin (Republic of Moldova) were tested for adsorption of toxic metal ions. Active carbons from the apple wood (CA-M) and nut sells (CA-N) were oxidized with nitric acid (sample CA-Mox) and mixture of nitric acid/urea (samples CA-Mox-u and CA-Nox-u) in order to improve their ion-exchange properties. Activated carbon surface functional groups were evaluated by the Boehm titration method. Obtained oxidized samples were tested for adsorption of toxic metal ions (Co, Sr, Cd, Pb, Hg, Cs) from aqueous solutions. The samples CA-Mox-u and CA-Mox showed the higher affinity for cobalt(II), strontium(II) and lead(II) ions. Obtained results (sorption isotherms, pH and conductivity values of equilibrium solutions) suggest the ion-exchange mechanism as the main one for adsorption of cobalt (II) ions on samples CA-Mox and CA-Mox-u.Comparative analysis of active carbons sorption capacity for toxic metal ions from solutions reveal the oxidized samples (CA-Mox, CA-Mox-u, CA-Nox-u) as efficient adsorbents. |
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