Environmental Engineering Reference
In-Depth Information
CHAPTER 1
Tian C. Zhang and Rao Y. Surampalli
1.1
Background
Nanotechnology involves research, development, control, and characterization of
materials or devices between the atomic and micrometer scales (usually at the 0.1-100
nm range). Generally, fabrication/applications of nanomaterials (NMs, materials that
contain nanoparticles, NPs) involve the following major steps: ultra-
miniaturization/molecular manufacturing of NPs, functionlization of NMs, incorporating
NMs into nanocomposites, and final product or application. NMs exhibit novel
properties that differ from those of bulk materials due to the interactions and physics
between atoms. In addition, properties of NMs can be manipulated via different
synthesizing methods (either top-down or bottom-up methods) that dictate the shape and
arrangement of atoms and molecules within the NMs. Because of their unique
properties, NMs have been used in many different sectors for all kinds of purposes.
Currently, environmental applications of nanotechnologies provide new
opportunities for us to detect, control, and remediate environmental pollutions.
However, as with any new technology or chemical substance, there is a potential for
harm to human and natural ecosystems from nanotechnology. For these reasons,
research related to environmental nanotechnology mainly focus on two major directions:
(a) synthesizing new NMs (e.g., magnetic NMs or nanomembranes) or developing new
techniques (e.g., nanosensors) for enhanced environmental protection; and (b) defining
the problems and processes that might occur in the two ecosystems by evaluating the
environmental and economic benefits/risks of new nanotechnologies.
Since the 1990s, studies in both directions have generated enough information.
It would be beneficial to overview these studies within the frame of applications and
implications of nanotechnology. In 2007, the ASCE's Technical Committee on
Hazardous, Toxic and Radioactive Waste identified nanotechnology for water
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