Conclusion
In this study, the surface of magnetic nano-Fe3O4 was
successfully loaded and modified by dioctyl phthalate (DOP) and
the produced sorbent was further combined with triethylenetetamine
in a solvent free procedure for the formation of a novel
magnetic nano-Fe3O4-DOP-TETA sorbent. The produced nanoparticles
were found in the order of 3.0–12.0 nm and characterized
by different shapes and morphologies, high magnetic properties
and good thermal stability. The surfaces of these magnetic nanosorbents
were also identified by the presence of a variety of surface
functional groups, certain incorporated selectivity properties and
good magnetic solid phase sorption behaviors. The experimental
controlling parameters affecting the metal sorption properties
were also studied and optimized and the results of Cd(II), Pb(II) and
Ni(II) up-take confirmed the high dependence on reaction pH,
contact time, sorbent dosage, effect of initial metal ion concentration
and presence of competing ions such as Cu(II). Generally, the
evaluated sorbents were characterized by strong tendency and
high selectivity characters toward binding with Cd(II) and Pb(II)
under all evaluated and optimized controlling conditions. The
potential applications of magnetic nano-sorbents as magnetic solid
phase extractors for Cd(II) and Pb(II) from drinking tap water,
industrial wastewater and sea water were evaluated using multistage
micro-column technique and excellent results were obtained
in the range of 82.3–100.0 3.0–5.0%, respectively.