Summary: | 碩士 === 國立高雄第一科技大學 === 環境與安全衛生工程所 === 94 === ABSTRACT
The aim of this study is to develop a Fenton oxidation/fluidization crystallization process for both removing chlorinated phenols and reducing the formed iron-containing sludge while the organic pollutant decompose. A typical persistent organic pollutant, 2,4-dichlorinephenol (2,4-DCP), is selected as the target compound for the investigation. Series of tests involving major experimental variables of solution pH level, H2O2 concentrations and its dosage ways, and iron concentrations are conducted for process development. Recycled scraped iron chip provides the iron source for the Fenton (or Fenton like) reaction and silicon sand is applied as the carrier for the fluidize bed reactor.
The experimental results shows that more than 99% of 2,4-DCP can be removed in a short reaction period by the fluidized bed Fenton (FBR-Fenton) process. The initial degradation rate of 2,4-DCP follows a pseudo first-order reaction kinetics. The achieved first-order reaction rate constants (k) of 2,4-DCP in various pH sloution are 0.2166, 0.0094 and 00.0101 min-1 for solution pH level equal to 3, 5 and 7, respectively. FBR-Fenton process not only can keep high degradation rate of 2,4-DCP as traditional homogenous Fenton process, but also up to 68% reduction in sludge production can be achieved at pH= 3. This investigation demonstrates the FBR-Fenton process is a
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advanced oxidation process taking both advantages of fast reaction and low sludge yield. In addition, the experimental results indicate that the derived iron-containing silicon sand pebbles can be further recycled as the catalyst for heterogeneous Fenton-like reactions even though their reaction rate is not so fast as the homogenous Fenton reaction.
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