Page 638 - Polymer-based Nanocomposites for Energy and Environmental Applications

Polymer nanocomposites for water treatments 589

contaminants. Further, nanocomposite materials enable higher process efficiency due
to the intrinsic unique characteristics of NPs, such as a high reaction rate.
Materials functionalized with NPs incorporated or deposited on their surface have
risk potentials, since NPs might be released and emitted to the environment where they
can accumulate for prolonged period. Furthermore, nanoengineered water technolo-
gies are rarely adaptable to mass processes and, at present, in many cases are not com-
petitive with conventional treatment technologies. Nevertheless, polymer
nanocomposite materials offer great potential for water innovations for the future,
in particular for decentralized treatment systems and point-of-use devices.

21.9 Recycling and recovery of polymer nanocomposites

The waste management hierarchy for waste prevention and management involves
prevention, preparing for reuse, recycling, recovery (e.g., energy recovery), and dis-
posal [76]. Recycling is an important method in the waste management hierarchy as
shown by the waste triangle (Fig. 21.17).
In practice, it covers a range of activities from product reuse to incineration com-
bined with energy recovery, known as thermal recycling.
Recycling implies the reuse of the polymer as polymer. Polymer nanocomposites
used for water treatment may be recycled in two ways [77]: (i) recycling of industrial

Most Prevention
favored
option
Minimization

Reuse
Recycling

Least Energy recovery
favored
option Disposal

Reduce Reuse

Landfill

Recycle Eliminate

Fig. 21.17 Waste minimization triangle.