Page 83 - IJES Special Issues for AIEC2016

International Journal of Environment and Sustainability, 2016, 5(1): 71-75 73

samples, X-ray data is multiphase and contains for Fe3O4 is optimal at pH 6.5. Efficiency of
magnetite (Fe3O4) – 70%, maghemite (γ- Fe2O3) extraction of cobalt and strontium increases
– 25% and goethite (FeOOH) – 5%. The pres- with increasing pH and reached maximum
ence of impurity phases goethite and maghe- values at pH 9.
mite Fe3O4 samples associated with aging and is
characteristic of the powders obtained from Figure 3: Photomicrograph of particles
aqueous solutions. annealed at 450°C obtained from nitrate solu-
tion with added ammonium chloride at pH 7
It is established that from nitrate solutions
formed shapeless large agglomerates of 50 –
200 microns (Figure 1a-c), consisting of
spherical particles of Fe2O3 (specific surface Ssp
= 150 m2/g). Introduction of chloride ions
(Figures 2, 3) leads to the formation of solid
particles of cubic and oval size of about 0.12 –
0.20 microns (Ssp = 30 m2/g). Sodium ion has no
significant effect on the formation of particles
Fe2O3 (Figure 4).

Unlike Fe2O3, Fe3O4 is not observed in the
formation of large agglomerates and the
powder is composed of spherical with a size of
from 0.5 um to several microns. The specific
surface area of Fe3O4 was 130 m2/g.

Figure 4: Photomicrograph of particles
annealed at 450°C obtained from nitrate solu-
tion with added ammonium bicarbonate at pH 9

Figure 2: Photomicrograph of particles The highest efficiency of extraction occurs on
annealed at 450°C obtained from chloride the particles of Fe3O4 and 95% to 68% cobalt
and strontium. Furthermore, for strontium in
solution at pH 9 the pH range 4 – 7, depending on the observed
additional peak recoveries in the range of pH
Figure 5 shows the degree of extraction of 5,2 – 5,7, which is more pronounced on Fe2O3
metals from the pH of the particles Fe2O3 particles (Figure 5a).
(Figure 5 a) and Fe3O4 (Figure 5 b). As can be
seen from Figure 5, iron oxide particles effec- Figure 6 shows the adsorption isotherms for the
tively recovered europium (97%), Ce (97%) and studied metals. Isotherms are S-type for
copper (92%). However, in an acidic medium, europium and copper and L-type cerium. This
using Fe2O3 particles as sorbents can achieve type of isotherm shows heterogeneity on the
high degrees of recovery of these metals as sorbent surface. The yield on the plateau is
compared with Fe3O4 particles. The maximum characteristic of the formation of a monolayer.
extraction for Fe2O3 is observed at pH 5.5, and

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