Environmental Engineering Reference
In-Depth Information
TABLE 13.4
Energy Use of Various Water Supply Alternatives
Water Supply Alternative
Energy Use (kWh/kgal)
Conventional treatment of surface water
0.8-1.5
Water reclamation
2.0-4.0
Indirect potable reuse
5.0-7.5
Brackish water desalination
3.0-5.0
Paciic Ocean water desalination
10.0-14.0
Source:
Based on Table 1 in N. Voutchkov,
Seawater Desalination: Current
Status and Challenges
, Water Globe Consulting LLC, Stamford, CT.
Voutchkov [15] noted that nanotubes are “promising” for future use and could allow for
membranes able to produce signiicantly more water than a conventional 8-in membrane.
13.10 Nanotechnology's Potential
Much of this chapter has examined water treatment and water use in a number of indus-
trial-related areas. In closing, we will take a brief look at nanotechnology. Other chapters
in this topic will examine this subject in much greater depth.
13.10.1 Next Step
Earlier in this chapter, we have touched on different water treatment technologies. Those
who have followed water treatment technologies for any time have seen changes occur
among the types of technologies used. IX proved better than zeolite softening, and RO in
turn has come to replace IX in a number of applications. Since the late 1980s, EDI has made
steady inroads into traditional deionization applications. Similar stories are found among
other types of water treatment and monitoring technologies.
Within the water business, the newest area of development involves nanotechnology. This
inal section will review reports from some individuals active in the development and com-
mercialization of nanotechnology in water treatment uses. These presentations are based on
presentations given at the 2009 Water Executive Forum conducted in Philadelphia.
13.10.2 Background
Broadly speaking, nanotechnology entails the manipulation of materials and objects at the
1-100 nanometer (nm) scale. The related materials may be incorporated into materials or
structures that are deined in terms of their size in nm. Unlike some areas, nanotechnol-
ogy includes aspects of a number of scientiic ields, including chemistry, physics, biology,
and material sciences, among others [18].
At present, it is unknown to what extent nanotechnology will inally inluence water
treatment. One development involves the use of nanomaterials in ilters and membranes.
The materials may be made to help a ilter or membrane selectively remove speciic con-
taminants. One example of a proposed product comes from Australia where scientists
have found that nanotubes made up of boron and nitrogen atoms are able to block salt
