碩士 / 國立成功大學 / 環境工程學系 / 103 / Cyanobacteria bloom is a common issue in potable water sources. Potassium ferrate (K2FeO4) is an effective oxidant that may be used as a pre-oxidant in water treatment processes. In addition, during the oxidation processes the Fe(VI) in ferrate will be reduced to Fe(III) or ferric hydroxide, further acting as a coagulant for the removal of cyanobacteria cells. Therefore, understanding the interaction between the ferrate based oxidant and cyanobacteria cells will provide a better basis for the application of this oxidant in water treatment processes. In this study, the impact of K2FeO4 on the cell viability of Microcystis aeruginosa and fate of the associated microcystins (MCs) in water was investigated. In addition, the potential of cyanobacteria removal in the pre-oxidation and followed coagulation system was assessed. In conducting the experiments, the parameters that may affect the oxidation and removal of cyanobacteria, such as pH, K2FeO4 residual and background water matrix were also evaluated in this study. Two Chick-Watson type models were used to describe the experimental data for cell integrity and MCs release and degradation. The results showed that water matrix could affect the rate of cell lysis caused by ferrate. In the experiment using RET reservoir water spiked with 1105 and 5105 cells/mL of M. aeruginosa, 10 mg/L of ferrate can effectively damage all the cells and degrade MCs in 3 hours, while for the experiment using water with higher organic matter and ions, CK lake water and ASM medium, only 23 and ~0% of cells were damaged at the same time scale, respectively, under application of 20 mg/L of ferrate. When cells were ruptured, MCs were found to release into water and degraded by ferrate quickly, leading to no accumulation of dissolved MCs in the water. The Chick-Watson type models were found to successfully simulate the change of cell integrity over time. The cell rupture models were further combined with kinetic model for MCs degradation for the simulation of MCs concentrations in the water. The MCs degradation model was found to predict the trend of observed MCs concentrations over time, suggesting that the model is reasonable.
| Identifer | oai:union.ndltd.org:TW/103NCKU5515030 |
| Date | January 2015 |
| Creators | Bo-HungLin, 林柏宏 |
| Contributors | Tsair-Fuh Lin, 林財富 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 103 |
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