Environmental Engineering Reference
In-Depth Information
molecules [19]. If successfully commercialized, this desalination method would represent
a new way to treat brackish and ocean waters. The major desalination methods currently
include different types of thermal distillation, and RO.
13.11 Research Work
The following are brief summaries of research work reported on at the 2009 Water
Executive Forum.
R. Sustich [20] reported on some different areas of development involving the use of
nanotechnology in water. Mr. Sustich is a coauthor of
Nanotechnology Applications for Clean
Water
, a topic that examines uses for nanotechnology in water treatment. Other coauthors
of the topic published by William Andrew Publishing (January 2009) include M. Diallo, J.
Duncan, N. Savage, and A. Street. The topic includes work from more than 80 researchers
and environmental professionals, primarily in the United States. Topics addressed include
drinking water, wastewater treatment and reuse, groundwater remediation, contaminant
monitoring, and social issues about the use of nanotechnology.
One example of research on the use of nanotechnologies in water treatment is the use
of photocatalytic titanium nanoparticles for contaminant oxidation and disinfection. One
application is to replace chlorine and other chemical disinfectants with titanium dioxide
(TiO
2
) in conjunction with UV light. TiO
2
improves the energy eficiency of the UV system
and also has been shown to have improved disinfection results.
Another approach is the use of nanotechnology-based membrane materials. In this sce-
nario, a thin-ilm composite membrane has nanoparticles dispersed on it to create a func-
tionalized membrane for the removal of speciic contaminants. One example is a thin-ilm
membrane supported by zero-valent iron (ZVI) and bimetallic nanoparticles for the pur-
pose of chlorine reduction.
In another instance, Sustich reported about nanoparticle pore-functionalized MF mem-
branes that have use for dechlorination. This method involves the use of PVDF mem-
branes modiied for uniform pore size. Types of nanoparticles used can include ZVI, iron/
nickel, and iron/zinc. Research has shown such membranes are capable of polychlorinated
biphenyl and trichloroethylene degradation.
A fourth example cited by Sustich involved research by V.V. Tarabara, a professor at
Michigan State University. Tarabara and his team have examined the use of multifunc-
tional nanotechnology-based membrane materials that are attached to, say, ceramic mem-
branes, resulting in “self-cleaning” catalytic surfaces. One goal is to develop membranes
with additional functionalities. Figure 13.1 [19] is a series of diagrams with different nano-
materials that could be afixed to the ilter surface.
13.11.1 Fullerenes
At the Water Executive Forum conference, M. Hotze [21] reported on fullerenes and their
potential use in water treatment. Fullerenes are a family of carbon allotropes that are
structurally similar to graphite and contain pentagonal or heptagonal rings. Other char-
acteristics are that they are hydrophobic and insoluble in water and can be dispersed in
water through various methods, of which solvent exchange and surfactant wrapping are
two examples.
