Better removal efficiencies are reported in the pH range of 7.9 to 8.6 (Saitoh et al.
2014). Alumina-coated multiwalled carbon nanotubes adsorbed 23 and Reactive
Blue 19 with adsorption coherence to Langmuir and Freundlich adsorption isotherm
model, respectively, showing pseudo-second-order kinetics (Malakootian et al.
2015).
The adsorption of 2 from aqueous solution with γ-Al 2 O 3 nanoparticles modified
by sodium dodecyl sulfate exhibited linear calibration graph over the range of
1.2–250 μg L
À1 with a relative standard deviation of 1.50% at 100 μg L
À1 , and
Langmuir adsorption isotherm model explained data appropriately with reasonable
adsorption efficiency, 72.4 mg g
À1 (Mohammadifar et al. 2015). Nano-alumina
adsorbed Reactive Red 120 dye from aqueous solution significantly at pH 3.0
ensuing Langmuir adsorption isotherm model and pseudo-second-order kinetics
(Nadafi et al. 2014). Similarly, aluminum-modified activated carbon as an adsorbent
removed 1 from aqueous solution with q max value of 182 mg g
À1 following Langmuir adsorption isotherm and pseudo-second-order kinetics (Kazeem et al. 2018).
Natural clay was used to remove nile blue and brilliant cresyl blue from the water
with a q max values of 25 and 42 mg g
À1 calculated from Freundlich adsorption
isotherm with pseudo-first-order kinetics (İyim and Güçlü 2009). Moroccan natural
clays removed 1, 2, and 8 from water when adsorption data of 1 and 2 correlated well
to Langmuir adsorption isotherm model and 8 to Dubinin-Radushkevitch isotherm
model with pseudo-second-order kinetics for dyes (Elmoubarki et al. 2015). The
ultrasound-assisted polymerization was carried out to synthesize poly(acrylic acid)
hydrogel composite by incorporating kaolin to remove brilliant green from solution
at pH 7. Adsorption data followed both Freundlich adsorption isotherm and Langmuir adsorption isotherm with pseudo-second-order kinetics (Shirsath et al. 2013).
Naturally occurring red clay also showed significant adsorption capacity
(125 mg g
À1 ) for brilliant green when extracted by batch process, and RedlichPeterson isotherm model explained the adsorption well. Moreover, adsorption data
followed pseudo-second-order kinetics (Rehman et al. 2013). The removal of brilliant red H-EGXL and Procion Yellow H-EXL dyes was studied using synthetic talc
and kaolin as adsorbents. A study showed that synthetic talc and kaolin performed
well in acidic conditions rather than neutral or alkaline media. The adsorption data
was best suited to Langmuir adsorption isotherm (Rahman et al. 2013). Similarly,
amino-functionalized attapulgite clay nanoparticle adsorbent uptake 1 from water
followed pseudo-second-order kinetics, and according to Langmuir adsorption isotherm model provided q max value as 215.73 mg g
À1 (Zhou et al. 2015).
The uptake of cationic dye 1 and anionic dye 6 from wastewater by
malachite@clay nanocomposites was reasonable with q max value of 277.77 and
238.09 mg g
À1 following Langmuir adsorption isotherm model and pseudo-secondorder kinetics. The results encouraged the application of malachite@clay
nanocomposite for better adsorption and dye removal from wastewater (Srivastava
and Sillanpää 2017). Another study on 6 was carried out using mixed adsorbents
with natural clay materials. The results showed coherence to Freundlich adsorption
isotherm and pseudo-second-order kinetics. Overall results were satisfactorily true
for the usage of mixed adsorbents with natural clay materials (Vimonses et al. 2010).
612
R. S. Ashraf et al.
2014). Alumina-coated multiwalled carbon nanotubes adsorbed 23 and Reactive
Blue 19 with adsorption coherence to Langmuir and Freundlich adsorption isotherm
model, respectively, showing pseudo-second-order kinetics (Malakootian et al.
2015).
The adsorption of 2 from aqueous solution with γ-Al 2 O 3 nanoparticles modified
by sodium dodecyl sulfate exhibited linear calibration graph over the range of
1.2–250 μg L
À1 with a relative standard deviation of 1.50% at 100 μg L
À1 , and
Langmuir adsorption isotherm model explained data appropriately with reasonable
adsorption efficiency, 72.4 mg g
À1 (Mohammadifar et al. 2015). Nano-alumina
adsorbed Reactive Red 120 dye from aqueous solution significantly at pH 3.0
ensuing Langmuir adsorption isotherm model and pseudo-second-order kinetics
(Nadafi et al. 2014). Similarly, aluminum-modified activated carbon as an adsorbent
removed 1 from aqueous solution with q max value of 182 mg g
À1 following Langmuir adsorption isotherm and pseudo-second-order kinetics (Kazeem et al. 2018).
Natural clay was used to remove nile blue and brilliant cresyl blue from the water
with a q max values of 25 and 42 mg g
À1 calculated from Freundlich adsorption
isotherm with pseudo-first-order kinetics (İyim and Güçlü 2009). Moroccan natural
clays removed 1, 2, and 8 from water when adsorption data of 1 and 2 correlated well
to Langmuir adsorption isotherm model and 8 to Dubinin-Radushkevitch isotherm
model with pseudo-second-order kinetics for dyes (Elmoubarki et al. 2015). The
ultrasound-assisted polymerization was carried out to synthesize poly(acrylic acid)
hydrogel composite by incorporating kaolin to remove brilliant green from solution
at pH 7. Adsorption data followed both Freundlich adsorption isotherm and Langmuir adsorption isotherm with pseudo-second-order kinetics (Shirsath et al. 2013).
Naturally occurring red clay also showed significant adsorption capacity
(125 mg g
À1 ) for brilliant green when extracted by batch process, and RedlichPeterson isotherm model explained the adsorption well. Moreover, adsorption data
followed pseudo-second-order kinetics (Rehman et al. 2013). The removal of brilliant red H-EGXL and Procion Yellow H-EXL dyes was studied using synthetic talc
and kaolin as adsorbents. A study showed that synthetic talc and kaolin performed
well in acidic conditions rather than neutral or alkaline media. The adsorption data
was best suited to Langmuir adsorption isotherm (Rahman et al. 2013). Similarly,
amino-functionalized attapulgite clay nanoparticle adsorbent uptake 1 from water
followed pseudo-second-order kinetics, and according to Langmuir adsorption isotherm model provided q max value as 215.73 mg g
À1 (Zhou et al. 2015).
The uptake of cationic dye 1 and anionic dye 6 from wastewater by
malachite@clay nanocomposites was reasonable with q max value of 277.77 and
238.09 mg g
À1 following Langmuir adsorption isotherm model and pseudo-secondorder kinetics. The results encouraged the application of malachite@clay
nanocomposite for better adsorption and dye removal from wastewater (Srivastava
and Sillanpää 2017). Another study on 6 was carried out using mixed adsorbents
with natural clay materials. The results showed coherence to Freundlich adsorption
isotherm and pseudo-second-order kinetics. Overall results were satisfactorily true
for the usage of mixed adsorbents with natural clay materials (Vimonses et al. 2010).
612
R. S. Ashraf et al.