RICARDO T. LOPES

Resultados de Busca

Agora exibindo 1 - 1 de 1

Removal efficiency of sup(75)Se, sup(51) Cr and sup(60)Co from tidal water by mangrove sediments from Sepetiba Bay (SE Brazil)
2014 - SUZUKI, K.N.; MACHADO, E.C.; MACHADO, W.; BELLIDO, A.V.B.; BELLIDO, L.F.; OSSO JUNIOR, J.A.; LOPES, R.T.
Mangrove sediment cores sampled from Sepetiba Bay (SE Brazil) were covered with tidal water spiked with 75Se, 51Cr and 60Co to evaluate the removal efficiency of these radiotracers by underlying sediments. Variable time-evolution trends were observed along 115 h experiments, with significant differences between removal efficiencies of all radiotracers observed only after 70 h ( 51Cr[60Co[75Se). After an event of 60Co release back to overlying water, there was a general trend of lower 60Co removal than observed for other radiotracers during the period from 20 to 54 h. After this event, alternated periods of higher 60Co and higher 75Se removal trends were observed, attributed to behavioural differences expected for such anionic and cationic radiotracers. While 75Se and 51Cr showed uniform time-evolution curves, as typically found in the literature for most radiotracers, 60Co removal rates presented oscillations, probably due to sensitivity to changes in redox conditions within underlying sediments. Results evidenced the role of mangrove sediments as trace element sinks, which have implications for coastal water quality and for possible uses of such sediments in wastewater treatment systems.