Page 490 - Polymer-based Nanocomposites for Energy and Environmental Applications

Interplay of polymer bionanocomposites and significance of ionic liquids for heavy metal removal 443

necessary to mention that most nanotechnology applications for water purification are
still at the laboratory-scale research stage today. The future expansion and market
implementation have to face a variety of challenges like cost-effectiveness, technical
hurdles, and potential environment and human risk [16]. A number of studies have
been published in recent years describing the possible role of nanotechnology, provid-
ing hygienic water in emerging countries by developing new and better technological
solutions for eliminating pollutants from wastewater [17].
In spite of several methods in literature for the elimination of heavy metal from
contaminated water, it can’t be used in every condition, due to different intrusions,
maintenance problems, and production and regulator of budgets and development.
New research has demonstrated that the extractive elimination of heavy metals with
ionic liquids (ILs) is gradually employed as a substitute for old industrial contami-
nated water process. Consequently, nowadays, various reviews have exposed ILs that
have been planned and developed to achieve a preferred function discussed as task-
specific ionic liquids (TSILs) [18]. Researchers now are able to enthusiastically out-
spread this procedure to TSILs developed from imidazolium, tetraalkylammonium,
pyridinium, pyrrolidinium, and phosphonium salts [18]. The application of TSILs
as powerful agents for the elimination of heavy metals like chromium, zinc, cadmium,
copper, mercury, lead, iron, and nickel has revealed fascinating results [19]. It was
observed that the hydrophobic ILs absorb heavy metals from aqueous solution when
added with contaminated water, and they eliminate the metal ions from contaminated
water. Moreover, to the ecological values, separation of metals from aqueous solu-
tions also has unlimited economic advantages in which retrieval of metals has been
fascinating the attention from metallurgists.
But, in this chapter, we have emphasized on water treatment skills related to bio-
based nanocomposites, which help as a monitor and motivation to those considering
nanoparticles materials in these areas together with a slight approach for ILs as sor-
bents. Initially, we observed the developments and applications in this particular area
and then discussed high potency bionanocomposite studies. We compiled key results
in the areas of remediation and water purification techniques that have auspicious gifts
to developing nanomaterials in water and wastewater technology.

16.1.1 Biosorption for removal of heavy metal ions
Biosorption is nothing but a process by which particular biomolecules (or biomass)
shows the ability to attach with certain ions or other molecules from aqueous solutions
[20]. Plenty of biomasses include bacteria, fungi, yeast, agricultural wastes, algae,
industrial wastes, and polysaccharides have been mentioned as biosorbents for the
exclusion of metals [21]. Polysaccharides like alginate, chitin, cellulose, and glycan
have confirmed metal-binding potential due to interactions with functional groups on
the surface. The large quantity of agricultural wastes, having natural materials with
cellulosic nature, makes them as potential low-cost biosorbents [22]. Biosorption
was investigated as an effective method to remove the suspended metals from dilute
complex solutions with extraordinary competence and fast intrinsic kinetics [23].As
compared with some other conventional techniques like chemical precipitation and