Page 386 - Environmental Nanotechnology Applications and Impacts of Nanomaterials

Chapter
10

Nanomaterials as Adsorbents

Mélanie Auffan University of Aix-Marseille, Aix-en-Provence, France
Heather J. Shipley Rice University, Houston, Texas, USA
Sujin Yean Rice University, Houston, Texas, USA
Amy T. Kan Rice University, Houston, Texas, USA
Mason Tomson Rice University, Houston, Texas, USA
Jerome Rose CNRS-University of Aix-Marseille, Aix-en-Provence, France
Jean-Yves Bottero CNRS-University of Aix-Marseille, Aix-en-Provence, France

Introduction
In recent years, drinking water regulations have continued to lower the
maximum contaminant level (MCL) for pollutants. For instance, in
2002, the World Health Organization (WHO) decided to reduce the
arsenic standard for drinking water from 50 g/L to 10 g/L. The stiff-
ening of regulations generates strong demands to improve methods for
removing pollutants from the water and controlling water-treatment
residuals. Currently, a wide range of physico-chemical and biological
methods are used and studied for the removal of organic and/or inorganic
contaminants from polluted waters (Sheoran and Sheoran, 2006).
Coagulation-flocculation, membrane processes, and adsorption are the
most common methods of contaminant removal. The most efficient and
low cost process for the removal of colloids and organics in water treat-
ment is the use of inorganic salts as coagulation-flocculation agents
such as Al 13 (Bottero et al., 1980; Bottero et al., 1982) and Fe 24 (Bottero
et al., 1993; Bottero et al., 1994) polycation species. However, this
approach has two disadvantages: a higher volume of sludge generated
and difficulty in recovering the metals for reuse. For water treatment,

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