adsorption isotherm model with 97% dye removal at pH 8. Adsorption kinetics
matched pseudo-second-order and thermodynamic process being endothermic and
spontaneous for the entire adsorption process (Ahmad et al. 2014).
In another study, modified durian seeds were evaluated for removing 3 from
aqueous solution with 92.52% efficiency at pH 6.0 and followed the
abovementioned adsorption isotherms, kinetics, and thermodynamic analysis
(Ahmad et al. 2015b). Papaya seed was chemically modified to eliminate 1 and
Congo red (6) from aqueous solution. The adsorption data for 1 fitted to Langmuir
and Freundlich adsorption isotherm models, while the adsorption kinetics obeyed
pseudo-second-order with high values of coefficient of correlation (R
2
! 0.99)
(Nasuha et al. 2011). Likewise, adsorption data of 1 by papaya seeds from aqueous
solutions correlated to the Langmuir adsorption isotherm model with a q max of
556 mg g
À1 with an initial concentration of 50–360 mgL
À1 , adsorbent dose and
pH in the range of 0.05–1.00 g to 3–10, respectively, at 30
C. The adsorption
kinetics followed pseudo-second-order kinetics (Hameed 2009; Mukhlish et al.
2012; Unuabonah et al. 2009).
The papaya seeds also exhibited adsorption of 440 mg g
À1 to remove Direct
Black 38, a tannery dye, following the Langmuir adsorption isotherm model and
second-order kinetic equation (Weber et al. 2013). Dye removal and decolorization
potential of rice husk against textile wastewater have been studied for 7, direct
orange, and magenta by optimization of influencing factors. Freundlich adsorption
isotherm and pseudo-first-order kinetics were obeyed (Verma and Mishra 2010;
Chakraborty et al. 2011).
Sorption of 1 was carried with rice husk activated carbon, which achieved
adsorption efficiency of over 97% at pH 10 and the initial concentration of
4 mg L
À1 (Rahman et al. 2012). Likewise, another study reported that activated
carbon developed from rice husk removed 2 from aqueous solutions and wastewaters using batch adsorption process with over 63 mg g
À1 adsorption efficiency
following Freundlich adsorption isotherm and Langmuir adsorption isotherm
models (Chowdhury et al. 2011; Sharma 2009).
In addition to the use of rice husk, rice husk ash has also demonstrated excellent
adsorption capability for 1 from aqueous medium (Sharma et al. 2010;
Ahmaruzzaman and Gupta 2011). Rice straw fly ash removed 85% of Reactive
Blue 19 (30–100 mg L
À1 ) at highly acidic pH within 1.0 h following Langmuir
adsorption isotherm and Freundlich adsorption isotherm models and pseudo-secondorder kinetics (Chakraborty et al. 2013b). 1 was removed from organo-modified rice
straw using batch adsorption process in which adsorption data correlated to the
Langmuir adsorption isotherm model with q max values of 296 and 145 mg/g for
modified and unmodified rice straw at 303 K following pseudo-second-order kinetics (Ebrahimian Pirbazari et al. 2016).
Another research endorsed the combination of white-rot fungus Phanerochaete
chrysosporium and rice straw as an efficient adsorbent for 1 with 88% uptake
efficiency from 400 mg/L of initial dye concentration (Cheng et al. 2015). The
adsorption process of Casuarina equisetifolia needle for methyl violet 2B followed
the Langmuir adsorption isotherm model with q max value of 164.99 mg/g with
606
R. S. Ashraf et al.
matched pseudo-second-order and thermodynamic process being endothermic and
spontaneous for the entire adsorption process (Ahmad et al. 2014).
In another study, modified durian seeds were evaluated for removing 3 from
aqueous solution with 92.52% efficiency at pH 6.0 and followed the
abovementioned adsorption isotherms, kinetics, and thermodynamic analysis
(Ahmad et al. 2015b). Papaya seed was chemically modified to eliminate 1 and
Congo red (6) from aqueous solution. The adsorption data for 1 fitted to Langmuir
and Freundlich adsorption isotherm models, while the adsorption kinetics obeyed
pseudo-second-order with high values of coefficient of correlation (R
2
! 0.99)
(Nasuha et al. 2011). Likewise, adsorption data of 1 by papaya seeds from aqueous
solutions correlated to the Langmuir adsorption isotherm model with a q max of
556 mg g
À1 with an initial concentration of 50–360 mgL
À1 , adsorbent dose and
pH in the range of 0.05–1.00 g to 3–10, respectively, at 30
C. The adsorption
kinetics followed pseudo-second-order kinetics (Hameed 2009; Mukhlish et al.
2012; Unuabonah et al. 2009).
The papaya seeds also exhibited adsorption of 440 mg g
À1 to remove Direct
Black 38, a tannery dye, following the Langmuir adsorption isotherm model and
second-order kinetic equation (Weber et al. 2013). Dye removal and decolorization
potential of rice husk against textile wastewater have been studied for 7, direct
orange, and magenta by optimization of influencing factors. Freundlich adsorption
isotherm and pseudo-first-order kinetics were obeyed (Verma and Mishra 2010;
Chakraborty et al. 2011).
Sorption of 1 was carried with rice husk activated carbon, which achieved
adsorption efficiency of over 97% at pH 10 and the initial concentration of
4 mg L
À1 (Rahman et al. 2012). Likewise, another study reported that activated
carbon developed from rice husk removed 2 from aqueous solutions and wastewaters using batch adsorption process with over 63 mg g
À1 adsorption efficiency
following Freundlich adsorption isotherm and Langmuir adsorption isotherm
models (Chowdhury et al. 2011; Sharma 2009).
In addition to the use of rice husk, rice husk ash has also demonstrated excellent
adsorption capability for 1 from aqueous medium (Sharma et al. 2010;
Ahmaruzzaman and Gupta 2011). Rice straw fly ash removed 85% of Reactive
Blue 19 (30–100 mg L
À1 ) at highly acidic pH within 1.0 h following Langmuir
adsorption isotherm and Freundlich adsorption isotherm models and pseudo-secondorder kinetics (Chakraborty et al. 2013b). 1 was removed from organo-modified rice
straw using batch adsorption process in which adsorption data correlated to the
Langmuir adsorption isotherm model with q max values of 296 and 145 mg/g for
modified and unmodified rice straw at 303 K following pseudo-second-order kinetics (Ebrahimian Pirbazari et al. 2016).
Another research endorsed the combination of white-rot fungus Phanerochaete
chrysosporium and rice straw as an efficient adsorbent for 1 with 88% uptake
efficiency from 400 mg/L of initial dye concentration (Cheng et al. 2015). The
adsorption process of Casuarina equisetifolia needle for methyl violet 2B followed
the Langmuir adsorption isotherm model with q max value of 164.99 mg/g with
606
R. S. Ashraf et al.