Photodegradation and Adsorption of Fast Green FCF in Tio2-Chitin Suspension
The potential of chitin as co-adsorbent in the photocatalytic degradation of Fast Green in titanium dioxide suspension was investigated. The physico-chemical characteristics of chitin were studied using Analysis of Surface Area and Porosity (ASAP), Fourier Transform Infrared Spectroscopy (FTIR) a...
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| Format: | Thesis |
| Language: | English English |
| Published: |
2005
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| Subjects: | |
| Online Access: | http://psasir.upm.edu.my/id/eprint/6238/1/FS_2005_26.pdf |
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| Summary: | The potential of chitin as co-adsorbent in the photocatalytic degradation of Fast Green
in titanium dioxide suspension was investigated. The physico-chemical characteristics
of chitin were studied using Analysis of Surface Area and Porosity (ASAP), Fourier
Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM).
The sorption study was first done and compared with titanium dioxide heterogeneous
photocatalysis. The result of kinetics studies indicates that the sorption process was
pH dependent and exothermic. The adsorption equilibrium was achieved after 60
minutes and the adsorption capacity increased as the dye concentration was increased.
The kinetic data was tested for first and pseudo-second kinetic order models and was
found to fit well to the latter, while the adsorption isotherm was found to agree well
with the Langmuir equation assuming monolayer type adsorption.The photocatalytic degradation and adsorption of Fast Green from aqueous solution
has been investigated in suspensions containing commercial titanium dioxide
(Degussa P-25), chitin and mixture of titanium dioxide-chitin. The removals of Fast
Green using a mixture of titanium dioxide-chitin were found to follow first order
kinetic. The presence of chitin in titanium dioxide suspension enhanced the removal
by two times higher. Fast Green removal using mixture of titanium dioxide-chitin
under UV irradiation was found to be more efficient rather than illumination using
titanium dioxide or chitin alone.
The removal of Fast Green using chitin and a mixture of titanium dioxide-chitin were
rapid for the first 30 minute and reached equilibrium after 1 hour. A synergy effect
was observed with an increase in the apparent rate constant by 1.86 times. This was
ascribed to an extended adsorption of Fast Green on chitin followed by a transfer to
titanium dioxide where it is photocatalytically degraded.
pH has significant effect on the adsorption and photodegradation properties of chitin
and titanium dioxide surface. However, the effect of temperature on adsorption and
photodegradation process using titanium dioxide-chitin mixture was minimal. This
combined photocatalytic-adsorption system appears promising as an efficient
accelerated removal process of organic pollutants from water. |
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