Page 457 - Polymer-based Nanocomposites for Energy and Environmental Applications

414 Polymer-based Nanocomposites for Energy and Environmental Applications

it was highlighted that the system has low operational cost when matched with other
types of MBR [86].
Some well-known “integration of nanotechnology with biological process for
wastewater purification systems” is discussed below:
a. Algal membrane bioreactor (A-MBR) with nanoparticles
b. Pretreatment of aerobic digestion with nanoparticles
c. Improvement of microbial fuel cell efficiency through nanotechnology
d. Integration of microbes with electrospun nanofibrous webs (NFW) for water purification
e. Integrated nanoparticles and biological process

The combination of biological process with advance nanotechnology for wastewater
purification system considered is the effective protocol for water purification [87].Up
to date, a variety of nanoparticles like CNT [88], TiO 2 [79], and ZnO 2 [89] have been
effectively studied for wastewater purification. It has been reported that using nano-
particle integration, the effectiveness of each biological process, for example,
A-MBR, MFC, and ASP, has been really enhanced than the another process using
alone. It has been studied that through nanoparticle integration, the efficiency of each
biological process, that is, A-MBR [90], MFC [91], and ASP [92], has been positively
enhanced than the process alone. According to the available date, it has also been
described that process efficiency, for instance, pollutant removal like nutrient
removal, has been enhanced up to 98.5% [93], dye decolorization up to 95%, and
BOD and COD drop up to 96% and 86%, respectively [87]. Shortly, this field of
research can offer competent and environmental friendly ways for wastewater reco-
very, but there are also some drawbacks while using these technologies. Among key
disadvantageous are the requirements of high level of technical study attitude and
methodology, specific biological agents for considering each pollutants (nutrients,
dyes, and organic compounds), and equilibrium level of each microbial and
nanoparticles accumulating in each technology on large scale.

15.6 Nanofiltration with forward osmosis

The osmosis phenomenon was first studied in 1748 by the French expert and cleric
Abb e Nollet [30]. Previously, animals and plant sources were used as membranes.
The first reported synthetic semipermeable membrane, which was a gelatinous film
of copper ferrocyanide in nature, was prepared by Traube [94].
Actually, a forward osmosis-nanofiltration (FO-NF) system is a new integrated
technology that was made up of flat-sheet cross flow module to separate reusable
water from coke-oven wastewater with minimum concentration polarization and
maximum flux using very minimum energy. Investigations were carried out under
different sets of operating conditions of pressure, cross flow rate, pH of the feed
solution, and run time for better understanding of the phenomena of concentration
polarization and reverse salt diffusion in the new system.
During the last few decades, a lot of research works are conducted to highlight the
wide applications in the field of biological application, for example, anoxic-oxic,