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Biosorptive uptake of Fe(2+), Cu(2+) and As(5+) by activated biochar derived from Colocasia esculenta: Isotherm, kinetics, thermodynamics, and cost estimation.

Banerjee S, Mukherjee S, LaminKa-Ot A, Joshi SR, Mandal T, Halder G - J Adv Res (2016)

Bottom Line: Adsorption of Fe(2+), Cu(2+) and As(5+) on to SSAB was found to be governed by pseudo-second order kinetic model.Regeneration of metal desorbed SSAB with 1 N sodium hydroxide maintained its effectiveness towards multiple metal adsorption cycles.Cost estimation of SSAB production substantiated its cost effectiveness as compared to commercially available activated carbon.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemical Engg, National Institute of Technology Durgapur, West Bengal, India.

ABSTRACT
The adsorptive capability of superheated steam activated biochar (SSAB) produced from Colocasia esculenta was investigated for removal of Cu(2+), Fe(2+) and As(5+) from simulated coal mine wastewater. SSAB was characterized by scanning electron microscopy, Fourier transform infrared spectroscopy and Brunauer-Emmett-Teller analyser. Adsorption isotherm indicated monolayer adsorption which fitted best in Langmuir isotherm model. Thermodynamic study suggested the removal process to be exothermic, feasible and spontaneous in nature. Adsorption of Fe(2+), Cu(2+) and As(5+) on to SSAB was found to be governed by pseudo-second order kinetic model. Efficacy of SSAB in terms of metal desorption, regeneration and reusability for multiple cycles was studied. Regeneration of metal desorbed SSAB with 1 N sodium hydroxide maintained its effectiveness towards multiple metal adsorption cycles. Cost estimation of SSAB production substantiated its cost effectiveness as compared to commercially available activated carbon. Hence, SSAB could be a promising adsorbent for metal ions removal from aqueous solution.

No MeSH data available.


Related in: MedlinePlus

Effect of (a) pH, (b) adsorbent dose, (c) agitation speed, (d) initial concentration, (e) contact time, and (f) temperature on Fe2+, Cu2+ and As5+ adsorption.
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f0015: Effect of (a) pH, (b) adsorbent dose, (c) agitation speed, (d) initial concentration, (e) contact time, and (f) temperature on Fe2+, Cu2+ and As5+ adsorption.

Mentions: Effect of pH on adsorptive removal of Fe2+, Cu2+ and As5+ using SSAB was studied within the pH range of 2–7. It is shown in Fig. 3a that adsorptive uptake of Fe2+, Cu2+ and As5+ depends highly on pH where with increase or decrease in pH, overall uptake capacity of the adsorbent changed. At lower pH, maximum adsorption of Fe2+ was observed. When initial pH of ferrous aqueous solution was increased from pH 2 to 3, a gradual increase in the metal uptake by SSAB was observed. At pH 3, after a steep increment of metal adsorption from pH 2, uptake capacity of SSAB reached its equilibrium with maximum removal of 78.94%. There was a decrease in Fe2+ ion adsorption onto SSAB as the pH was increased from 3 to 7. This can be attributed to the fact that the predominant ferrous species [Fe(H2O)6]2+ found at lower pH fails to interact with adsorbent surface since with increase in pH, the number of [Fe(OH)(H2O)5]+ also increases [46], [47] thereby leaving lesser surface for ferrous ion to interact with the adsorbent. Due to the increase in [Fe(OH)(H2O)5]+ species, precipitation of Fe2+ into Fe(OH)3 increases resulting in less adsorption of Fe2+ at higher pH [48]. Similarly, adsorption of Cu2+ and As5+ onto SSAB under the influence of pH was studied. In case of Cu2+ and As5+, removal percentage increased with increase in pH. In Fig. 3a, it can be clearly seen that at pH 5 and 6, the adsorbent was able to remove Cu2+ and As5+ with a maximum removal of 79.66% and 74.74% respectively, whereas at lower pH, it was unable to remove Cu2+ and As5+ at a considerate amount. This may be due to the affinity of SSAB towards H+ ions which increases at higher concentration of H+ ions. This increase in H+ ions prevents bond formation between the heavy metal ions and the adsorbent surface. Thus, it can be clearly said that SSAB has the capability to adsorb various metal contaminants at various pH levels.


Biosorptive uptake of Fe(2+), Cu(2+) and As(5+) by activated biochar derived from Colocasia esculenta: Isotherm, kinetics, thermodynamics, and cost estimation.

Banerjee S, Mukherjee S, LaminKa-Ot A, Joshi SR, Mandal T, Halder G - J Adv Res (2016)

Effect of (a) pH, (b) adsorbent dose, (c) agitation speed, (d) initial concentration, (e) contact time, and (f) temperature on Fe2+, Cu2+ and As5+ adsorption.
© Copyright Policy - CC BY-NC-ND
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4933041&req=5

f0015: Effect of (a) pH, (b) adsorbent dose, (c) agitation speed, (d) initial concentration, (e) contact time, and (f) temperature on Fe2+, Cu2+ and As5+ adsorption.
Mentions: Effect of pH on adsorptive removal of Fe2+, Cu2+ and As5+ using SSAB was studied within the pH range of 2–7. It is shown in Fig. 3a that adsorptive uptake of Fe2+, Cu2+ and As5+ depends highly on pH where with increase or decrease in pH, overall uptake capacity of the adsorbent changed. At lower pH, maximum adsorption of Fe2+ was observed. When initial pH of ferrous aqueous solution was increased from pH 2 to 3, a gradual increase in the metal uptake by SSAB was observed. At pH 3, after a steep increment of metal adsorption from pH 2, uptake capacity of SSAB reached its equilibrium with maximum removal of 78.94%. There was a decrease in Fe2+ ion adsorption onto SSAB as the pH was increased from 3 to 7. This can be attributed to the fact that the predominant ferrous species [Fe(H2O)6]2+ found at lower pH fails to interact with adsorbent surface since with increase in pH, the number of [Fe(OH)(H2O)5]+ also increases [46], [47] thereby leaving lesser surface for ferrous ion to interact with the adsorbent. Due to the increase in [Fe(OH)(H2O)5]+ species, precipitation of Fe2+ into Fe(OH)3 increases resulting in less adsorption of Fe2+ at higher pH [48]. Similarly, adsorption of Cu2+ and As5+ onto SSAB under the influence of pH was studied. In case of Cu2+ and As5+, removal percentage increased with increase in pH. In Fig. 3a, it can be clearly seen that at pH 5 and 6, the adsorbent was able to remove Cu2+ and As5+ with a maximum removal of 79.66% and 74.74% respectively, whereas at lower pH, it was unable to remove Cu2+ and As5+ at a considerate amount. This may be due to the affinity of SSAB towards H+ ions which increases at higher concentration of H+ ions. This increase in H+ ions prevents bond formation between the heavy metal ions and the adsorbent surface. Thus, it can be clearly said that SSAB has the capability to adsorb various metal contaminants at various pH levels.

Bottom Line: Adsorption of Fe(2+), Cu(2+) and As(5+) on to SSAB was found to be governed by pseudo-second order kinetic model.Regeneration of metal desorbed SSAB with 1 N sodium hydroxide maintained its effectiveness towards multiple metal adsorption cycles.Cost estimation of SSAB production substantiated its cost effectiveness as compared to commercially available activated carbon.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemical Engg, National Institute of Technology Durgapur, West Bengal, India.

ABSTRACT
The adsorptive capability of superheated steam activated biochar (SSAB) produced from Colocasia esculenta was investigated for removal of Cu(2+), Fe(2+) and As(5+) from simulated coal mine wastewater. SSAB was characterized by scanning electron microscopy, Fourier transform infrared spectroscopy and Brunauer-Emmett-Teller analyser. Adsorption isotherm indicated monolayer adsorption which fitted best in Langmuir isotherm model. Thermodynamic study suggested the removal process to be exothermic, feasible and spontaneous in nature. Adsorption of Fe(2+), Cu(2+) and As(5+) on to SSAB was found to be governed by pseudo-second order kinetic model. Efficacy of SSAB in terms of metal desorption, regeneration and reusability for multiple cycles was studied. Regeneration of metal desorbed SSAB with 1 N sodium hydroxide maintained its effectiveness towards multiple metal adsorption cycles. Cost estimation of SSAB production substantiated its cost effectiveness as compared to commercially available activated carbon. Hence, SSAB could be a promising adsorbent for metal ions removal from aqueous solution.

No MeSH data available.


Related in: MedlinePlus