碩士 / 淡江大學 / 化學工程與材料工程學系碩士班 / 103 / Hybrid cross-flow microfiltration systems for pretreatment of seawater desalination were studied. The permeate flux and quality among different operations, such as hydrophilic membranes with different pore size, dynamic membrane formed by powder activated carbon (PAC), dynamic membrane coupled with coagulation operation, were measured and compared. The PAC dynamic membranes, constructed by pre-coating PAC on the primary membrane, was used for removing organic material and inorganic fine particles in seawater to prevent the membrane fouling in following Reverse Osmosis (RO) units.
Artificial seawater was filtered using 0.1 μm MCE membrane, the filtration flux increased 70% as the transmembrane pressure increased from 100 to 180 kPa. However, the flux decayed more quickly under higher pressures. The membrane resistance of the PAC dynamic membrane was 21% lower than that of 0.1 μm MCE membrane even under high transmembrane pressures. It was attributed to the large PAC particle size and loose packing structure of dynamic membrane. When PAC dynamic membrane was used for filtering artificial seawater, the flux increased with increasing transmembrane pressure. However, the flux declined dramatically at the beginning of filtration, the major resistance sources were those organic materials adsorbed and captured in PAC dynamic membranes. Three kinds of coagulants, ferric chloride, aluminum sulfate and chitosan, were used to enlarge floc sizes, . The results of jar tester indicated that the use of chitosan with a dose of 5 mg/L was optimal. To combine coagulation operations with cross-flow filtration processes, either the use of 0.1 μm MCE membrane or PAC dynamic membrane, the flux was improved. Comparing the performances of different operations, the hybrid system coupled with coagulation and PAC dynamic membrane behaved the highest efficiency of pollutant removal and highest permeate flux. The quality of permeate water, DOC, COD, turbidity and concentration of humic acid, for each operation was measured. The permeate quality met the requirement of RO feed.,
| Identifer | oai:union.ndltd.org:TW/103TKU05063004 |
| Date | January 2015 |
| Creators | Chiao-Wei Cheng, 鄭喬維 |
| Contributors | Kuo-Jen Hwang, 黃國楨 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 92 |
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