Nanotechnology for domestic water purification - Nanotechnology in Eco-efficient Construction - page 363

Nanotechnology is increasingly being identifi ed as an area of science and
technology that could play a role in addressing some of the shortcomings
of conventional POU devices. Studies by Brame et al. (2011), Theron et al. ,
(2008) and Watlington (2005) suggest that nanotechnology-based materials
could lead to cheaper, more durable, and more effi cient water treatment
technologies that meet the needs of developing countries. Several water
treatment methods and devices that incorporate nanoscale materials are
already commercially available, and others are being developed. These
nanotechnology-based products include water fi lters, fi ltration membranes,
catalysts, and nanoparticles for groundwater remediation. However, a well-
defi ned and well-engineered nano-based product needs to address signifi -
cant challenges before a suitable POU device for household use can be
commercialized to take care of the safe-water needs of the poor as well as
the rich.
The present chapter aims to provide readers with a review of the practical
applications of nanomaterials in the water sector. In the following sections,
an overview of the different types of nanomaterials (e.g., metal and metal
oxide nanoparticles, carbon nanotubes, zeolites, dendrimers, etc.) presently
in use for water treatment applications is provided along with the different
methods of nanomaterials synthesis. Subsequent sections discuss the envi-
ronmental and health implications of the use of nanomaterials. Finally, the
chapter focuses on the challenges associated with development of practical
nano-based water purifi cation systems.

16.2 Nanomaterials and water purifi cation

There are a number of studies (Diallo et al. , 2009; Cloete et al. , 2010; Hotze
and Lowry, 2010) highlighting the importance of nanostructured materials
in the fi eld of water purifi cation, desalination, wastewater treatment, water
recycle and reuse. Nanomaterials have shown their potential not only in
water treatment, but also in water quality monitoring through sensing and
detection. However, we shall restrict our discussion to water treatment
applications within the confi nement of water purifi cation only. The specifi c
issues regarding application modalities with respect to a household (domes-
tic) scale are addressed in Section 16.7.

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16.3 The need for nanomaterials

in water purifi cation

The variation in the quality and quantity of water available across the globe
is drastically different and hence it is mandatory to have different kinds of
region-specifi c solutions. The already scarce water resource is becoming
increasingly scarce because of rapid population growth and ceaseless