abstract
It is demonstrated that colloidal magnetite nanoparticles can be used as nanosorbents for lanthanide ions dissolved in water. In particular, a series of experiments are performed for the removal of Eu(III) in distinct analytical conditions and by applying an external magnet to collect the sorbents previously dispersed in water samples. Furthermore, strategies for surface chemistry functionalization are also investigated, aiming to investigate the effect of this parameter on the removal capacity of the Fe3O4 nanoparticles. The supernatant solutions are monitored for the remaining amount of Eu(III) by fluorescence emission measurements in the presence of 2,6-pyridinedicarboxylic acid as a sensitizer. The results demonstrate that neat Fe3O4 nanoparticles are capable of capturing lanthanide ions (III) from aqueous solutions (pH 7), without need of surface modification, and for subsequent removal by magnetic separation. During the removal, efficiency is increased after modifying the particles' surfaces with silica and 3-aminopropyltrimethoxysilane; in alkaline medium (pH 10), there is complete removal regardless the type of nanosorbent used. This has been explained by the formation of insoluble Eu(III) species that adsorb strongly to the nanosorbents surfaces allowing their subsequent magnetic separation.
keywords
IRON-OXIDE NANOPARTICLES; RARE-EARTH IONS; AQUEOUS-SOLUTION; ADSORPTION BEHAVIOR; CARBON NANOTUBES; WASTE-WATER; DYE REMOVAL; EU(III); SORPTION; SEPARATION
subject category
Chemistry; Science & Technology - Other Topics; Materials Science
authors
Carvalho, RS; Daniel-da-Silva, AL; Trindade, T
our authors
Ana Luísa Daniel da Silva
Principal Researcher
Rui Filipe Silva Carvalho
Research Fellowship
Tito Trindade
Full professorProjects
acknowledgements
The authors thank funding by FCT (Fundacao para a Ciencia e a Tecnologia) through the Project PTDC/CTM-NAN/120668/2010, by FEDER through program COMPETE, and by national funding through FCT in the frame of Project CICECO - FCOMP-01-0124-FEDER-037271 (Ref. FCT Pest-C/CTM/LA0011/2013).