Environmental Engineering Reference
In-Depth Information
CHAPTER 16
Engineered Nanomaterials
Paul Westerhoff
As opposed to the numerous environmental benefits from nanotechnology to
improve the quality of water that is addressed throughout this topic, the environmental
exposure and potential adverse risk from nanomaterials (NMs) in water is currently ill-
defined. Technologies to produce NMs, and commercial products containing NMs are
just now being developed. Although over 500 commercial products in the USA alone
claim to contain NMs (
http://www.nanotechproject.org/,
2007), the annual production
quantity of most NMs remains low. Development and validation is lacking of analytical
techniques to detect NMs at environmentally relevant concentrations. Consequently,
there are no reports of engineered NMs actually occurring in aquatic systems yet.
However, the scientific community wants to be cautious about environmental
implications of nanotechnology (Balbus et al., 2007; Scheufele et al., 2007), thus
warranting a critical evaluation of NMs in water as a potential emerging contaminant.
This chapter presents a holistic view of NMs in water. It begins with a discussion
for why NMs should be considered emerging contaminants. Literature is summarized
that describes similarities between natural and engineered NMs and associated analytical
techniques that could be useful for detecting engineered NMs in aquatic systems. Next,
several scenarios are introduced that begin to provide a framework for understanding the
potential occurrence and fate of engineered NMs in water. It is important to note that
currently very little information is available on engineered NM sources, occurrence, fate
or toxicity in the environment; this information is in its infancy of being researched (e.g.,
(Maynard et al., 2006)). Therefore, the chapter concludes with identification of obstacles
that should be overcome to determine the relevance of engineered NMs in aquatic
systems.
558
Search WWH ::
Custom Search