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E. Emekdar and U. K. ¸
Sahin
Bhattacharyya and Ray worked on removing synthetic dyes from waters via microand nanocomposites of bentonite filled with chitosan and acrylic copolymer. They
used FTIR, XRD, SEM, DTA, and TGA for the evaluation of their results. The best
swelling ratio in water was yield with a comonomer ratio of acrylic acid and acrylamide 7.5:1, and the highest adsorption for methyl violet and Congo red dye was
yield with chitosan which is 12 wt% of total monomer weight in a polymethacrylic
acid gel. The highest swelling of clay including hydrogel samples was 2 wt% nanosized clay (NF2) and 4 wt% micro-sized clay (MF4). When all samples were treated
with methyl violet and malachite green dyes with different concentrations, adsorption amount from high to low was, respectively, NF2, MF4, and F0. Furthermore,
it was seen that methyl violet adsorption is less than malachite green, and adsorption characteristics were well-fitting with first- and second-order kinetics, and the
combined Langmuir–Freundlich model [66].
Bulut and Karaer examined adsorption of a composite including cross-linked
chitosan and bentonite for methylene blue which is a cationic dyestuff to remove
the dyestuff from aqueous solution. By using FTIR, it was seen that the maximum
adsorption capacity of the dyestuff was 95.24 mg/g at 298 °K, and thermodynamic
and kinetics of the process were well-fitting with Langmuir model [67].
Liua et al. used a composite including cross-linked chitosan and bentonite to
removing Amino Black 10B(AB10B) which is an anionic azo dye and adsorption
behavior. The results of the study were tested with FTIR, SEM, XRD, and TGA. It
was observed that removing AB10B decreased when pH and dye concentration of the
solution were increased while the removal increased when contact time and dosage of
adsorbent were increased. Time for reaching the equilibrium was extended when the
initial dye concentration was increased. Moreover, kinetic and equilibrium behavior
were well-fitting, respectively, with the Langmuir model and pseudo-second-order
kinetic model. Maximum adsorption capacity values were yield at 313 °K with natural
pH as 350.9 mg/g and at 293 °K with pH 2 as 323.6 mg/g. As understood from this
data, relatively high temperatures and low pH are more suitable for adsorption of the
dyestuff [68].
Guo et al. studied for removing of dyestuff from wastewater by a composite
including chitosan and CTAB-modified bentonite. 1CTS–10 CTAB-bentonite was
prepared and used for weak acid scarlet adsorption which resulted in more than 85%
adsorption efficiency; thus, it was a very good adsorbent composite that was reusable
for three cycles. For the testing stage, FTIR and XRD are used, and it was seen that
the adsorption behavior of the composite was well-fitting with Langmuir and Temkin
models [69].
Mahdavinia and Karami synthesized a nanocomposite that is magnetic
carboxymethyl chitosan-poly(acrylamide)/laponite RD with improved dye adsorption capacity. They used X-ray diffraction, transmittance electron microscopy, thermogravimetric analysis, vibrating sample magnetometer, and scanning electron
microscopy techniques for the testing stage. It was clear that water absorbency is
related to magnetic laponite RD content, and when the amount of magnetic clay
increased, the swelling capacity and salt sensitivity decreased, while dye removing
and adsorption capacity at acidic medium increased. Besides, analyses were done
E. Emekdar and U. K. ¸
Sahin
Bhattacharyya and Ray worked on removing synthetic dyes from waters via microand nanocomposites of bentonite filled with chitosan and acrylic copolymer. They
used FTIR, XRD, SEM, DTA, and TGA for the evaluation of their results. The best
swelling ratio in water was yield with a comonomer ratio of acrylic acid and acrylamide 7.5:1, and the highest adsorption for methyl violet and Congo red dye was
yield with chitosan which is 12 wt% of total monomer weight in a polymethacrylic
acid gel. The highest swelling of clay including hydrogel samples was 2 wt% nanosized clay (NF2) and 4 wt% micro-sized clay (MF4). When all samples were treated
with methyl violet and malachite green dyes with different concentrations, adsorption amount from high to low was, respectively, NF2, MF4, and F0. Furthermore,
it was seen that methyl violet adsorption is less than malachite green, and adsorption characteristics were well-fitting with first- and second-order kinetics, and the
combined Langmuir–Freundlich model [66].
Bulut and Karaer examined adsorption of a composite including cross-linked
chitosan and bentonite for methylene blue which is a cationic dyestuff to remove
the dyestuff from aqueous solution. By using FTIR, it was seen that the maximum
adsorption capacity of the dyestuff was 95.24 mg/g at 298 °K, and thermodynamic
and kinetics of the process were well-fitting with Langmuir model [67].
Liua et al. used a composite including cross-linked chitosan and bentonite to
removing Amino Black 10B(AB10B) which is an anionic azo dye and adsorption
behavior. The results of the study were tested with FTIR, SEM, XRD, and TGA. It
was observed that removing AB10B decreased when pH and dye concentration of the
solution were increased while the removal increased when contact time and dosage of
adsorbent were increased. Time for reaching the equilibrium was extended when the
initial dye concentration was increased. Moreover, kinetic and equilibrium behavior
were well-fitting, respectively, with the Langmuir model and pseudo-second-order
kinetic model. Maximum adsorption capacity values were yield at 313 °K with natural
pH as 350.9 mg/g and at 293 °K with pH 2 as 323.6 mg/g. As understood from this
data, relatively high temperatures and low pH are more suitable for adsorption of the
dyestuff [68].
Guo et al. studied for removing of dyestuff from wastewater by a composite
including chitosan and CTAB-modified bentonite. 1CTS–10 CTAB-bentonite was
prepared and used for weak acid scarlet adsorption which resulted in more than 85%
adsorption efficiency; thus, it was a very good adsorbent composite that was reusable
for three cycles. For the testing stage, FTIR and XRD are used, and it was seen that
the adsorption behavior of the composite was well-fitting with Langmuir and Temkin
models [69].
Mahdavinia and Karami synthesized a nanocomposite that is magnetic
carboxymethyl chitosan-poly(acrylamide)/laponite RD with improved dye adsorption capacity. They used X-ray diffraction, transmittance electron microscopy, thermogravimetric analysis, vibrating sample magnetometer, and scanning electron
microscopy techniques for the testing stage. It was clear that water absorbency is
related to magnetic laponite RD content, and when the amount of magnetic clay
increased, the swelling capacity and salt sensitivity decreased, while dye removing
and adsorption capacity at acidic medium increased. Besides, analyses were done