Nevertheless, other researchers found the reduction in the adsorption limit after
recovery. Saiz et al. (2014) investigated the recovery and reusability of arsenateadsorbed Fe 3 O 4 @SiO 2 composite materials. 0.01 M concentration of NaOH and
HCl was used for the desorption process and found that NaOH performance much
better in the desorption process. This alkaline treatment was further explored to
assess the long-term execution of the recovery procedure, in which adsorbent
materials were involved in functionalization steps (i.e., protonation of amino groups
and coordination of Fe
2+ ) after each of the desorption process. After five cycles of
adsorption-desorption process, 26% reduction in the desorption and 5.7% reduction
in the re-adsorption process was observed. Deliyanni et al. (2003) also revealed the
reduction in the adsorption capacity in an examination with respect to the adsorption
of arsenate ions by akageneite-type nanoparticles. In addition, approximately 30% of
akageneite’s ability was lost in every recovery period, which implies that the
adsorbent should be replaced after four recovery process.
Furthermore, metal oxide nanomaterials could be effectively recovered and
recycled for the expulsion of arsenic provided that the adsorption limits are pretty
much consistent even after a few cycles of recovery. This might be a benefit of
utilizing nanoparticles as an adsorbent to reduce heavy metals in drinking water.
Maybe some nanomaterials not holding their adsorption limit during recovery, this is
probably not a drawback confining their potential usage as the preparation of these
nano-adsorbent is very simple and the reagents used for their preparation is readily
available and very cheap (Saiz et al. 2014). Additionally, these nanomaterials
generally have high adsorption limits that could exceed the expenses expected to
replace the absorbent after a few cycles.
6.11 Stability Issues
Nanomaterials was proved to be viable in the elimination of substantial metal ions
from drinking water. Nevertheless, since they are typically exist as ultra-fine particles with low energy barriers which make them aggregate and accomplish a stabilized level (Petosa et al. 2010). Cluster formation of the nanoparticles reduces their
specific surface area, thereby diminishing their adsorption limit and reactivity (Tang
and Lo 2013). Additionally, the particle’s mobility reduces, that further adds to
decreasing their capability. To defeat the issues related with cluster formation, two
solutions were accounted.
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T. S. Sakthivel et al.
recovery. Saiz et al. (2014) investigated the recovery and reusability of arsenateadsorbed Fe 3 O 4 @SiO 2 composite materials. 0.01 M concentration of NaOH and
HCl was used for the desorption process and found that NaOH performance much
better in the desorption process. This alkaline treatment was further explored to
assess the long-term execution of the recovery procedure, in which adsorbent
materials were involved in functionalization steps (i.e., protonation of amino groups
and coordination of Fe
2+ ) after each of the desorption process. After five cycles of
adsorption-desorption process, 26% reduction in the desorption and 5.7% reduction
in the re-adsorption process was observed. Deliyanni et al. (2003) also revealed the
reduction in the adsorption capacity in an examination with respect to the adsorption
of arsenate ions by akageneite-type nanoparticles. In addition, approximately 30% of
akageneite’s ability was lost in every recovery period, which implies that the
adsorbent should be replaced after four recovery process.
Furthermore, metal oxide nanomaterials could be effectively recovered and
recycled for the expulsion of arsenic provided that the adsorption limits are pretty
much consistent even after a few cycles of recovery. This might be a benefit of
utilizing nanoparticles as an adsorbent to reduce heavy metals in drinking water.
Maybe some nanomaterials not holding their adsorption limit during recovery, this is
probably not a drawback confining their potential usage as the preparation of these
nano-adsorbent is very simple and the reagents used for their preparation is readily
available and very cheap (Saiz et al. 2014). Additionally, these nanomaterials
generally have high adsorption limits that could exceed the expenses expected to
replace the absorbent after a few cycles.
6.11 Stability Issues
Nanomaterials was proved to be viable in the elimination of substantial metal ions
from drinking water. Nevertheless, since they are typically exist as ultra-fine particles with low energy barriers which make them aggregate and accomplish a stabilized level (Petosa et al. 2010). Cluster formation of the nanoparticles reduces their
specific surface area, thereby diminishing their adsorption limit and reactivity (Tang
and Lo 2013). Additionally, the particle’s mobility reduces, that further adds to
decreasing their capability. To defeat the issues related with cluster formation, two
solutions were accounted.
184
T. S. Sakthivel et al.