Page 616 - Polymer-based Nanocomposites for Energy and Environmental Applications

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Polymer nanocomposites for 21

water treatments

N.B. Singh*, A.B.H. Susan †
†
*Sharda University, Greater Noida, India, University of Dhaka, Dhaka, Bangladesh

21.1 Introduction

Nature has provided plenty of resources that are used to sustain and develop life on the
planet. One of the most important resources available to us is water, which was present
long before the evolution of life. Access to clean water is considered one of the most
basic humanitarian goals and remains a major global challenge in the 21st century.
About 71% of the Earth’s surface is covered with water. According to a World Health
Organization fact sheet and other sources, the total amount of water present on earth is
97% saltwater and the remaining 3% is generally freshwater; of that 70% is frozen
freshwater in polar ice caps and glaciers, and the rest is mostly present as soil moisture
or lies in underground aquifers [1,2]. Overall, the freshwater that is available for use is
1% or 0.007% of the total water on earth, which is really very little. The water dis-
tribution on the earth is given in Fig. 21.1 [3,4].
The quality of water is deteriorating due to a number of factors such as the rise of
urbanization, population growth, industrial production, climate change, and other fac-
tors. Release of a huge quantity of organic and inorganic pollutants due to rapid indus-
trialization and urbanization is affecting the quality of natural water, which causes
water pollution. Freshwater can be contaminated with a number of pollutants ranging
from potentially toxic elements, dyes, phenolic compounds, pesticides, herbicides,
pharmaceuticals, personal care products, and many others. These pollutants can have
bioaccumulative, persistent, carcinogenic, mutagenic, and detrimental effects on the
survival of aquatic organisms, flora, fauna, and human health [5]. Water contamina-
tion is a big challenge to scientists because it is continuously increasing threats to both
human health and environment [6]. Therefore, removal of contaminants from water
has become a necessity. A large number of techniques such as precipitation, coagu-
lation, flocculation, incineration, ion exchange, reverse osmosis, membrane filtration,
electrochemistry, photo electrochemistry, advanced oxidation processes (AOPs),
adsorption, and biological methods are being used for the purification of water [7].
The ability to remove toxic contaminants from wastewater to a safe level and doing
so rapidly, efficiently, and within reasonable costs is important. Nanotechnology
could play an important role in this regard.
Nanotechnology, the engineering and art of manipulating matter at the nanoscale
(1–100 nm), offers the potential of novel nanomaterials for treatment of surface water,
groundwater, and wastewater contaminated by toxic materials [8–10]. Out of all

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