(194ab) Development of Low Cost Magnetic Adsorbents of Gum Karaya and Poly(N-isopropylacrylamide-co-acrylamide) to Remove Brilliant Green Dye from Aqueous Solution

Development
of low cost magnetic adsorbents of Gum karaya and
poly(N-isopropylacrylamide-co-acrylamide) to remove brilliant green dye from aqueous
solution

Anjali Goyal, Hemant
Mittal and Saeed Alhassan^*

Department of Chemical
Engineering, Khalifa University of Science and Technology,        PO Box 2533,
Abu Dhabi, United Arab Emirates

In
this work we have reported the synthesis of low cost magnetic nanocomposite
hydrogels (MNHCs) of poly(N-isopropylacrylamide (NIPAM)-co-acrylamide (AAM))
grafted gum karaya (GK) and magnetic nanoparticles (MNPs) to adsorb brilliant
green (BG) dye from wastewater. Initially, MNPs were synthesized from corn starch
under low temperature hydrothermal technique under saline conditions,
thereafter, MNHCs were synthesized by incorporating MNPs within the polymer
matrix of GK-cl-P(NIPAM-co-AAM). MNHCs were characterized using different
techniques such as FTIR, SEM, TEM and XRD. Adsorption of BG onto MNHCs was
found to be dependent upon different adsorption variables such as adsorbent
dosage and solution pH. The adsorption isotherm followed monolayer Langmuir
isotherm model, whereas, the adsorption kinetics followed pseudo-second-order
rate equation. Furthermore, thermodynamic parameters suggested that the
adsorption process was endothermic in nature and the magnitude of free enthalpy
changes predicted that physical forces were involved in the adsorption process.
MNHCs were successfully applied for the five consecutive cycles of
adsorption-desorption. Therefore, the MNHCs have proved their capabilities to
be used as promising adsorbents for the removal of cationic dyes from wastewater.