4. The sorbents could be infinitely recycled many times and this is best property of
nanosorbents and the process should be reversible so that we can get our
adsorbent back.
5. The Nanoparticles show high adsorption capacity.
4.4.1 Alumina Nanoparticles for Water Remediation
Alumina is generally known as corundum. It is white oxide and having several
phases such as gamma, delta, theta, and alpha. Out of these four phases alpha
alumina is the most thermodynamically stable phase. Alumina has many interesting
properties, for example high hardness, high stability, high insulation, and transparency (DeFriend et al. 2003). Nanosized Al 2 O 3 can be prepared by various methods
and has been employed as solid phase extraction materials for separation/
preconcentration of trace pollutants. Functional groups containing donors atoms
such as nitrogen, oxygen, and phosphorus have improved selectivity and sensitivity
of the nanoparticles and this is done by physical and chemical modifications. (Saha
and Sarkar 2012; Dousová et al. 2006; Pacheco et al. 2006; Medina et al. 2010).
O Al
SH
O
O
CH 2
CH 3
H 2 C
CH 3
CH 2
C
H 3
Al 2 O 3 –3-mercaptopropyltriethoxysilane nanoparticles
O Al
NH 2
O
O
CH 2
CH 3
H 2 C
CH 3
CH 2
C
H 3
Al 2 O 3 –3-aminoropyltriethoxysilane nanoparticles
4 Nanoscavengers for the Waste Water Remediation
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