Development of highly active supported TiO2 photocatalyst for waste water purification /
Ground water pollution has become one of the major concerns to the government due to the rapid development of the industries such as pharmaceutical and petrochemical. An excessive amount of polluted water release from these industries can cause negative impact to the public when the water is consume...
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Main Author: | |
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Format: | Thesis |
Language: | English |
Published: |
Gombak, Selangor :
Kulliyyah of Engineering, International Islamic University Malaysia,
2010
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Subjects: | |
Online Access: | http://studentrepo.iium.edu.my/handle/123456789/4632 |
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Summary: | Ground water pollution has become one of the major concerns to the government due to the rapid development of the industries such as pharmaceutical and petrochemical. An excessive amount of polluted water release from these industries can cause negative impact to the public when the water is consumed. Utilization of membrane filtration, chloride dioxide, and activated carbon are among conventional methods to treat the polluted water to date. Today, TiO2 photocatalyst is recognized as a potential material for water treatment as it is non-toxic and requires solar energy to initiate its redox mechanism to degrade organic and inorganic pollutants. Nonetheless, separation of TiO2 powder from the purified water after the treatment can be very tedious thus secondary operation is needed to separate them. In this research, TiO2 photocatalyst powders with nanosize particles were synthesized via sol-gel method. The mol ratios of water-to-TPT were varied at 0.5 (Powder 0.5), 1 (Powder 1), 2 (Powder 2), 3 (Powder 3), 4 (Powder 4), and 5 (Powder 5). Then, the gel TiO2 powders were dried at 200 °C for one hour followed by calcination at 400 °C. The obtained powders were then immobilized with cement for phenol degradation. FESEM surface morphologies of TiO2 powders showed that the powders had spherical shape at lower ratios of water-to-TPT and lost its ability to form homogeneous spherical shape as the ratios became higher. XRD analysis proved the obtained TiO2 powders were pure anatase and fully crystalline after being calcined at 400 °C. The TG/DTA results revealed the crystallization temperature of smaller powder particle was higher as it needed more heat to change its phase than bigger powder particles. The cement-bonded TiO2 photocatalysts were found to be well-adhered to the cement surface when analyzed with FESEM. Photocatalytic performance of cement-bonded TiO2 photocatalysts of Powder 1, 2, and 5 were evaluated from their photodegradation activity with phenol solution as the representative organic pollutant. Langmuir-Hinshelwood (L-H) model was employed to compare their photoefficiency. Powder 1 has higher value of adsorption equilibrium constant due to its smaller particles that capable of adsorbing more phenol molecules to be degraded. Meanwhile, Powder 2 has better reaction rate constant as its high crystallinity has provided efficient charge separation to induce the redox mechanism in degrading phenol molecules. |
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Item Description: | "A thesis submitted in fulfilment of the requirement for the degree of Master of Science (Material Engineering)"--On t.p. |
Physical Description: | xvi, 137 leaves : ill. ; 30 cm. |
Bibliography: | Includes bibliographical references leaves (119-130) |