Environmental Engineering Reference
In-Depth Information
15
ApplicAtion of nAnoAdsorbents
in WAter treAtment
Amit Bhatnagar
1
and Mika Sillanpää
2
1
Department of Biology and Environmental Science, Faculty of Health and Life Sciences, Linnaeus University, Kalmar, Sweden
2
Laboratory of Green Chemistry, Department of Energy and Environmental Technology, Faculty of Technology, Lappeenranta University
of Technology, Mikkeli, Finland
15.1
introduction
Water is a scarce resource, and with the pressures of climate change, rapid industrialization, and population growth, water
has become even scarcer, especially in developing regions. It is estimated that about one-sixth of the population living in
developing countries have no access to clean drinking water, while about 2.6 billion people do not have access to basic san-
itation facilities [1]. This situation becomes worse with contamination of water by a wide variety of toxic pollutants from
natural, domestic, or industrial sources. Despite their presence at low concentration ranges, environmental pollutants pose
serious threats to freshwater supply, living organisms, and public health. Water pollution is one of the critical problems of the
twenty-first century that humanity is facing. The quest to ensure that all people have access to clean drinking water is now
enshrined in the United Nations' (UN) Millennium Development Goals, which aim to halve the proportion of people without
sustainable access to safe drinking water by 2015. Robust and technological improvements are urgently required to treat pol-
luted water economically and efficiently. In recent years, various technologies have been developed to address this problem
[2, 3]. Among them, adsorption has been found very promising to remove diverse types of pollutants from water and waste-
water [4]. One of the most prominent examples of a conventional adsorbent for environmental application is activated carbon
[5]. This conventional material is cost-effective in application and thus widespread in the European drinking water industry
for water purification. However, in recent years, nanotechnology has emerged as a powerful platform, among other twenty-
first-century technologies, and various nanoadsorbents have been developed and tested toward water treatment applications
[6]. Nanostructured adsorbents offer the opportunity of an even greater adsorption capacity and might be designed to target
specific contaminants. Nanotechnology, related to the manipulation of materials and systems at the nanoscale (<100 nm), is
considered one of the most important achievements in science and technology. At the nanoscale, materials show unique char-
acteristics and, because of their small size, they possess a large surface area and “surface area to volume” ratio [7]. In this
regard, promoting nanoadsorbents presents opportunities to develop local and practical solutions for tackling global water
pollution. This chapter presents a brief overview of the technical applicability of different nanoadsorbents for removing various
aquatic pollutants. Present challenges, future research directions, and potential implications to public health, resulting from
their applications in water treatment, are also discussed.
