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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.


Adsorption mechanism of Fe2+, Cu2+ and As5+ on to SSAB. (a) Proposed bonding of Fe2+, Cu2+ and As5+ with carboxylic acid. (b) Proposed bonding of Fe2+, Cu2+ and As5+ with phenol.
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f0030: Adsorption mechanism of Fe2+, Cu2+ and As5+ on to SSAB. (a) Proposed bonding of Fe2+, Cu2+ and As5+ with carboxylic acid. (b) Proposed bonding of Fe2+, Cu2+ and As5+ with phenol.

Mentions: It is important to understand the inherent mechanism of metal adsorption onto adsorbent. Solubility of the solute (adsorbate) and affinity of particular solute ion onto adsorbent are two important resultant driving forces of an adsorption mechanism. These driving forces may be due to the type of bonding which exists between an adsorbent and adsorbate. On this aspect, FTIR analysis helps in understanding the underlying mechanism of an adsorption process. Apart from the functional groups present on SSAB, the above mentioned process parameters also played an important role in culminating the sorptive mechanism. Taking into account, this work presents a description of Fe2+, Cu2+ and As5+ adsorption on to SSAB. The FTIR analysis suggests the presence of carboxylic acids, aldehydes, aromatic groups, terminal alkynes, alcohols and phenols as functional groups on SSAB. Among these functional groups, carboxylic acid and phenol were found to be responsible for adsorption of these metal ions. Carboxylic acid is polar in nature, which donates and accepts both H+ and OH− groups due to the presence of carbonyl and hydroxyl groups, whereas, phenol consists of both phenyl (—C6H5) and hydroxyl group (—OH). Presence of multiple functional groups on an adsorbent generates higher possibilities of adsorbate and adsorbent interactions. Metal binds on to adsorbent by complexation and hydrolysis mediated adsorption. Shifting of —OH stretch after metal adsorption suggests hydrogen bonding. In metal adsorption, permanence of complexes is established mostly by the basicity of donor cluster, i.e., greater the basicity, greater is the stability of the complexes. In case of Cu2+, Fe2+ and As5+, the —OH group played an important role in bonding with the adsorbent. In general, metal fixes on to carbon by ligand formation and via ion-exchange. In our study, all the three ions formed ligands with the functional groups by replacing H+ with metal ions creating an organometallic complex on the adsorbent surface as it can be seen in Scheme 1. Though both phenol and carboxylic acid took part in the metal adhesion, the metal ion chemistry and its affinity created an overall difference it their overall uptake [45].


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)

Adsorption mechanism of Fe2+, Cu2+ and As5+ on to SSAB. (a) Proposed bonding of Fe2+, Cu2+ and As5+ with carboxylic acid. (b) Proposed bonding of Fe2+, Cu2+ and As5+ with phenol.
© Copyright Policy - CC BY-NC-ND
Related In: Results  -  Collection

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

f0030: Adsorption mechanism of Fe2+, Cu2+ and As5+ on to SSAB. (a) Proposed bonding of Fe2+, Cu2+ and As5+ with carboxylic acid. (b) Proposed bonding of Fe2+, Cu2+ and As5+ with phenol.
Mentions: It is important to understand the inherent mechanism of metal adsorption onto adsorbent. Solubility of the solute (adsorbate) and affinity of particular solute ion onto adsorbent are two important resultant driving forces of an adsorption mechanism. These driving forces may be due to the type of bonding which exists between an adsorbent and adsorbate. On this aspect, FTIR analysis helps in understanding the underlying mechanism of an adsorption process. Apart from the functional groups present on SSAB, the above mentioned process parameters also played an important role in culminating the sorptive mechanism. Taking into account, this work presents a description of Fe2+, Cu2+ and As5+ adsorption on to SSAB. The FTIR analysis suggests the presence of carboxylic acids, aldehydes, aromatic groups, terminal alkynes, alcohols and phenols as functional groups on SSAB. Among these functional groups, carboxylic acid and phenol were found to be responsible for adsorption of these metal ions. Carboxylic acid is polar in nature, which donates and accepts both H+ and OH− groups due to the presence of carbonyl and hydroxyl groups, whereas, phenol consists of both phenyl (—C6H5) and hydroxyl group (—OH). Presence of multiple functional groups on an adsorbent generates higher possibilities of adsorbate and adsorbent interactions. Metal binds on to adsorbent by complexation and hydrolysis mediated adsorption. Shifting of —OH stretch after metal adsorption suggests hydrogen bonding. In metal adsorption, permanence of complexes is established mostly by the basicity of donor cluster, i.e., greater the basicity, greater is the stability of the complexes. In case of Cu2+, Fe2+ and As5+, the —OH group played an important role in bonding with the adsorbent. In general, metal fixes on to carbon by ligand formation and via ion-exchange. In our study, all the three ions formed ligands with the functional groups by replacing H+ with metal ions creating an organometallic complex on the adsorbent surface as it can be seen in Scheme 1. Though both phenol and carboxylic acid took part in the metal adhesion, the metal ion chemistry and its affinity created an overall difference it their overall uptake [45].

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.