Lead sorption by carbon nanofibers grown on powdered activated carbon — kinetics and equilibrium
Carbon nano¯bers (CNFs) were synthesized by using a safe and less hazardous method, compared to using °oating catalysts in chemical vapor deposition (CVD) process. This process used C2H2 as carbon source and oil palm kernel shell-based powdered activated carbon (PAC) as cheap solid substrate. Use...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
World Scientic Publishing Company
2015
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| Subjects: | |
| Online Access: | http://irep.iium.edu.my/41433/ http://irep.iium.edu.my/41433/ http://irep.iium.edu.my/41433/ http://irep.iium.edu.my/41433/1/Published_Paper_Kinetics.pdf |
| Summary: | Carbon nano¯bers (CNFs) were synthesized by using a safe and less hazardous method, compared
to using °oating catalysts in chemical vapor deposition (CVD) process. This process used
C2H2 as carbon source and oil palm kernel shell-based powdered activated carbon (PAC) as cheap
solid substrate. Use of nickel (Ni2þ) impregnated PAC as ¯xed substrate for the synthesis of CNF
is one of the novelties of the research work accomplished by the authors. The PAC–CNFs porous
nanocomposite product was used for the sorption of lead ions (Pb2þ) from synthetic aqueous
solution. Kinetics of Pb2þ adsorption and isotherms were investigated by varying initial concentration
of lead and contact time. PAC–CNFs were found to remove Pb2þ better at acidic pH
of about 5.5. Langmuir and Freundlich isotherms were applied to the sorption equilibrium data to
¯nd the best ¯tted model. Langmuir isotherm model with R2 ¼ 0:965 ¯tted the adsorption data
better than the Freundlich isotherm. The kinetic processes of Pb2þ adsorption on CNFs were
investigated by applying di®erent kinetic models, namely zero-order, pseudo-¯rst-order and
pseudo-second-order. The pseudo-second-order rate equation exhibited the best results with
R2 ¼ 0:999, qe
¼ 74:79 (mg/g) and K2
¼ 0:029 (min . g=mg). The novel nanocomposite product
seemed to have the potential to remove Pb2þ ions from aqueous solution. |
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