Wastewater Herein, a simple two-step co-precipitation and hydrothermal

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Wastewater Herein, a simple two-step co-precipitation and hydrothermal

Wastewater
engendered by the textile industries is known to consist of a noticeable amount
of untreated dyes. The removing of dyes before discharging those textile
wastewaters is seriously crucial to preserving the natural water bodies and our
environment. Decolorization of the dye compounds performs a promising path for
textile wastewater treatment and thus, development of new nano hybrid
adsorbents will be of strong enthusiasm. Herein, a simple two-step
co-precipitation and hydrothermal methods has been hired to successfully
synthesize a series of a novel poly ethylene glycol (PEG) and layered double
hydroxide (LDH) modified magnetic iron oxide nanoparticles (MIONPs) with
different poly ethylene glycol molecular weights. The electrostatic interaction
between the negatively charged PEG-MIONPs and the positively charged LDH
nanocrystals is sufficient to induce the formation of stable self-assembly of
the two nano components. It is a kind of novel and high-efficiency absorbents
for the removal of methyl orange (MO) from aqueous solution. The as-synthesized
products were characterized by transmission electron microscopy (TEM), scanning
electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transformation
infrared spectroscopy (FTIR). Experimental parameters, such as nanoadsorbent
dosage, initial dye concentration, contact time, solution pH, ionic strength
and thermodynamics were investigated. The nano hybrids adsorbents lead to fast
adsorption kinetics and high adsorption capacity of the MO dye via quick surface
adsorption. At 600 mg L-1 dye solution, only 15
min was required to reach 95% adsorption and about 50% of the MO was adsorbed
in 2 min.  Kinetics data was well fitting by a
pseudosecond- order model compare to pseudofirst- order model, so it indicating
that adsorption was the rate limiting step. The equilibrium adsorption data
were interpreted using the Langmuir, Freundlich, and Temkin isotherm models,
which fitted well to both the Langmuir (R2 = 0.9693) and Freundlich
(R2 = 0.9710) models and the theoretical maximum adsorption capacity
was 1203 mg g?1. Furthermore, the desorption studies of MO using 0.1 M HCl and 0.1 NaOH
showed the reusability of the adsorbents

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