الفهرس 
1- IntroductionOnly 14 pages are availabe for public view
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Abstract
The synthesis and developments of magnetic chitosan nanoparticles for
high efficiency removal of the cadmium ions from aquatic medium are one of
the most challenging techniques. Highly adsorptive composite (MCH-ATA)
was produced by the reaction of chitosan with formaldehyde and amino thiazole
derivative. The sorbent was characterized by FTIR, elemental analyses (EA),
SEM-EDX, TEM analysis, TGA and titration (volumetric). The modified
material includes high nitrogen and sulfur contents (i.e., 4.64 and 1.35 mmol
g
−1
, respectively), compared to the pristine material (3.5 and 0 mmol g−1,
respectively). The sorption was investigated for the removal of Cd(II) ions from
synthetic solution before being tested towards naturally contaminated
groundwater in an industrial area. The functionalized sorbent shows a high
loading capacity (1.78 mmol Cd g−1; 200 mg Cd g−1) compared to the pristine
material (0.61 mmol Cdg−1; 68.57 mg Cd g−1), while removal of about 98% of
Cd with capacity (6.4 mg Cdg−1) from polymetallic contaminated groundwater.
The sorbent displays fast sorption kinetics compared to the non-modified
composite (MCH); 30 min is sufficient for complete sorption for MCH-ATA,
while 60–90 min for the MCH. PFORE (pseudo-first-order rate equation ) fits
sorption kinetics for both sorbents, whereas the Langmuir equation fits for
MCH and Langmuir and Sips for MCH-ATA for sorption isotherms. The TEM
analysis confirms the nano scale size, which limits the diffusion to intraparticle
sorption properties. The 0.2 M HCl solution is a successful desorbing agent for
the metal ions. The sorbent was applied for the removal of cadmium ions from
the contaminated underground water and appears to be a promising process for
metal decontamination and water treatment.
Development of bio-based sorbents (i.e., chitosan moieties) at nanoscale
size for the removal of metal contaminants is the main target of this research.
Grafting with thiazole heterocyclic derivative gives fast kinetics sorption, highly metal loading, and good recyclability for mining leaching solution. Different
analyses tools including (thermogravimetric analysis (TGA), scanning electron
microscope and energy dispersive spectroscopy (SEM-EDX), X-ray diffraction
(XRD), Fourier transform infrared (FTIR), BET surface area (nitrogen sorption
desorption), titration, and TEM (transmission electron microscopy)) were used
to investigate the chemical and textural properties of the functionalized sorbent.
The sorption was measured in normal visible light and under UV
emission. The highest capacity was measured at pH 5, which reached 0.251
mmol Pb g−1 in visible light compared with 0.346 mmol Pb g−1 under UV for
the pristine crosslinked chitosan (MCc). The sorption performances were
improved by functionalization; (0.7814 and 1.014 mmol Pb g−1) for the
functionalized sorbent (MCa-ATA) under visible light and UV, respectively.
PFORE (pseudo-first-order rate equation) and RIDE (resistance to intraparticle
diffusion) fit kinetics, the Sips equation is the most fit profile for the sorption
isotherms for the MCc in either light and UV processes, while PFORE and
RIDE for kinetics under light and UV for MCa-ATA and Sips in light and Sips
and Langmuir under the UV emission. Finally, the sorbent was investigated
toward a raffinate solution from ore processing and shows promising extraction
tools for the most interesting elements.