Nanoscale Porous Materials for Water Treatment: Advances and Challenges - Nanotechnologies for Water Environment Applications - page 325

Table 11.5 Summary of alumina-based porous materials applied for water treatment.
Alumina-
Compound

Pore
Size
(nm)

Surface
Area
(m 2 /g)

Target
Comp'd

Results Ref.

Mesoporous
Alumina

As(V): 121 mg of As(V)/g
As(III): 47 mg of As(III)/g

(Kim et
al., 2004)

3.5 307 Arsenic

Aminated
Mesoporous
Alumina

Copper ion is removed by > 95%
from 10 ppm solution

(Rengara
j et al.,
2004)

Cu 2+ 3.9 299

Cd's K d ( m 3 /g) 1.0 x 10 -2
Se(III)'s K d (m 3 /g): 1.1 x 10 -3

(Papelis
et al.,
1995)

Transition
Aluminas

Cd and
Se(II)

2 < 200

TCE conversion starts from 5% at
443 K and rises to very high values
in the 673-873 K ranges, with the
CO 2 yield being 99% at the same
temperature ranges. HCl and Cl 2
are the other main products with
little halogenated VOC
intermediates

-Alumina-
Supported
Manganese
Oxide

(Tseng et
al., 2003)

11.5 128 TCE

At 443 K and 1.5 MPa, 65% of
total organic carbon (TOC) and
99% color were removed after 3 h
treatment

(Zhang
and
Chuang,
1999)

Pd-Pt-
Ce/Alumina
Catalyst

TOC
and
Color

- 102

Using a post-hydrolysis method, Kim et al. (2004) have developed mesoporous
alumina (MA) with a high surface area of 307 m 2 /g, a uniform pore size of 3.5 nm and a
sponge like interlinked pore system. The resulting MA is insoluble and stable within the
pH range of 37. The maximum uptake of As(V) by MA is found to be 7 times higher
[121 mg of As(V)/g and 47 mg of As(III)/g] than that of the conventional AA; the
adsorption kinetics is also rapid, with complete adsorption in < 5 h, as compared to the
conventional AA (about 2 d to reach half of the equilibrium value). A desorption study
using sodium hydroxide solutions (0.011 M) is conducted, and more than 85% of the
arsenic adsorbed to the MA is desorbed in less than 1 h. These studies show that MA
with a wide surface area, a uniform pore size, and an interlinked pore system can be
used as an efficient adsorbent for the removal of arsenic (Kim et al., 2004).

Shin et al. (2004) tested aluminum-impregnated mesoporous adsorbents to
remove phosphate in water. To understand the effect of surface properties on the
adsorption behavior of phosphate, the surface structure of the materials was investigated
with X-ray diffraction (XRD), a N 2 adsorption-desorption technique, FTIR, and X-ray
photoelectron spectroscopy (XPS). The mesoporous materials were loaded with Al
components by reaction with surface silanol groups. In the adsorption test, the Al-