process (Visa and Duta 2013). Besides, hydrothermally modified fly ash can also be
applied for dye removal as well as the removal of heavy metals (Visa and Chelaru
2014). An interesting study represented the usage of fly ash synthesized from natural
adsorbent zeolite to remove 1 from wastewater using a batch method. Adsorption
data followed Langmuir adsorption isotherm, and kinetics obeyed the pseudosecond-order model (Chunfeng et al. 2009).
Further, alkaline-treated biomass fly ash demonstrated noteworthy removal of 10
with adsorption efficiency of 107.53 mg g
À1 at pH 8.2–10.4 as provided by the
Langmuir adsorption isotherm model with pseudo-second-order kinetics
(Pengthamkeerati et al. 2010). In another study, activated carbon and fly ash were
optimized to remove lignin-based materials from industrial effluents. The experimental data of adsorption correlated well to the Langmuir and Freundlich adsorption
isotherm models for both adsorbents. The adsorbent capacities obtained from the
Langmuir adsorption isotherm equation were 256 mg g
À1 (activated carbon) and
17 mg g
À1 (fly ash) at 60
C. The thermodynamic studies revealed the sorption onto
fly ash as exothermic and activated charcoal as endothermic (Andersson et al. 2011).
Another study involving the combined usage of fly ash adsorption and Fenton
oxidation for the removal of 9 showed good results. The chemical oxygen demand
(98%) was removed by the combined method, and chemical oxygen demand
removal capacity of fly ash for Fenton-treated 9 solution was 41 times greater than
that for untreated 9 solution (Chang et al. 2009).
Modified red mud was applied against bisphenol (17), and optimal results of 82%
adsorption were obtained by increasing the experiment duration and dose of adsorbent at pH 3. The results were following the Freundlich adsorption isotherm model
and provided the pseudo-second-order kinetics (Zazouli et al. 2013a). Acid-activated
sintering process red mud also successfully adsorbed 2 and 7 using batch experiment
at a pH of 3.2. Adsorption data suited well to Langmuir adsorption isotherm model
and q max of over 60 and 336 mg/g for 7 and 2 were obtained, respectively, with
pseudo-second-order kinetics and endothermic nature for 2 and exothermic for
7 (Zhang et al. 2014).
In another investigation, CO 2 -neutralized activated red mud was applied to
remove Safranin O by response surface methodology at an optimal pH of 8.3
following Langmuir adsorption isotherm model and provided the q max value of
9.7680 mg g
À1 (Sahu et al. 2015). The adsorptive removal of remazol brilliant
blue solution using red mud was studied considering the basic experimental parameters. The results correlated with the Langmuir adsorption isotherm model with an
adsorption capacity of red mud as 28.0 mg g
À1 at 40
C and pseudo-second-order
kinetics (Ratnamala et al. 2012).
Using activated red mud, Acid Blue 113 and 10 removal was studied with
different reaction parameters. The red mud was found to have a higher removal
efficiency of Acid Blue 113 than 10 at pH 3.0. The results obeyed pseudo-secondorder kinetics and Freundlich adsorption isotherm model with maximum adsorption
capacities as 83.3 and 35.5 mg/g for Acid Blue 113 and 10, respectively (ShirzadSiboni et al. 2014).
17 Methods for the Treatment of Wastewaters Containing Dyes and Pigments
609
applied for dye removal as well as the removal of heavy metals (Visa and Chelaru
2014). An interesting study represented the usage of fly ash synthesized from natural
adsorbent zeolite to remove 1 from wastewater using a batch method. Adsorption
data followed Langmuir adsorption isotherm, and kinetics obeyed the pseudosecond-order model (Chunfeng et al. 2009).
Further, alkaline-treated biomass fly ash demonstrated noteworthy removal of 10
with adsorption efficiency of 107.53 mg g
À1 at pH 8.2–10.4 as provided by the
Langmuir adsorption isotherm model with pseudo-second-order kinetics
(Pengthamkeerati et al. 2010). In another study, activated carbon and fly ash were
optimized to remove lignin-based materials from industrial effluents. The experimental data of adsorption correlated well to the Langmuir and Freundlich adsorption
isotherm models for both adsorbents. The adsorbent capacities obtained from the
Langmuir adsorption isotherm equation were 256 mg g
À1 (activated carbon) and
17 mg g
À1 (fly ash) at 60
C. The thermodynamic studies revealed the sorption onto
fly ash as exothermic and activated charcoal as endothermic (Andersson et al. 2011).
Another study involving the combined usage of fly ash adsorption and Fenton
oxidation for the removal of 9 showed good results. The chemical oxygen demand
(98%) was removed by the combined method, and chemical oxygen demand
removal capacity of fly ash for Fenton-treated 9 solution was 41 times greater than
that for untreated 9 solution (Chang et al. 2009).
Modified red mud was applied against bisphenol (17), and optimal results of 82%
adsorption were obtained by increasing the experiment duration and dose of adsorbent at pH 3. The results were following the Freundlich adsorption isotherm model
and provided the pseudo-second-order kinetics (Zazouli et al. 2013a). Acid-activated
sintering process red mud also successfully adsorbed 2 and 7 using batch experiment
at a pH of 3.2. Adsorption data suited well to Langmuir adsorption isotherm model
and q max of over 60 and 336 mg/g for 7 and 2 were obtained, respectively, with
pseudo-second-order kinetics and endothermic nature for 2 and exothermic for
7 (Zhang et al. 2014).
In another investigation, CO 2 -neutralized activated red mud was applied to
remove Safranin O by response surface methodology at an optimal pH of 8.3
following Langmuir adsorption isotherm model and provided the q max value of
9.7680 mg g
À1 (Sahu et al. 2015). The adsorptive removal of remazol brilliant
blue solution using red mud was studied considering the basic experimental parameters. The results correlated with the Langmuir adsorption isotherm model with an
adsorption capacity of red mud as 28.0 mg g
À1 at 40
C and pseudo-second-order
kinetics (Ratnamala et al. 2012).
Using activated red mud, Acid Blue 113 and 10 removal was studied with
different reaction parameters. The red mud was found to have a higher removal
efficiency of Acid Blue 113 than 10 at pH 3.0. The results obeyed pseudo-secondorder kinetics and Freundlich adsorption isotherm model with maximum adsorption
capacities as 83.3 and 35.5 mg/g for Acid Blue 113 and 10, respectively (ShirzadSiboni et al. 2014).
17 Methods for the Treatment of Wastewaters Containing Dyes and Pigments
609