博士 / 淡江大學 / 化學工程與材料工程學系碩士班 / 104 / Hybrid submergedmicrofiltration systemsforpretreatment ofseawater desalinationwere studied. The permeate flux and water quality among different operations, such as 0.45μm hydrophilic membranes, dynamic membrane formed bypowder activated carbon (PAC), dynamic membrane coupled with coagulation operationwere measured and compared.The PAC dynamic membranes, constructed bypre-coatingPAC on the primarymembrane,were used forabsordingorganic material andinorganic fine particles in seawater to prevent the membrane fouling in following Reverse Osmosis(RO) units.
Artificial seawater was filtered using0.45μm PVDFmembrane, the filtration flux increased30% asthe transmembrane pressure increased from 40 to 80kPa. However,the flux decayed more quickly under higher pressures.The membrane resistance of the PAC dynamic membrane was133%higherthan that of 0.45μm PVDF membraneunder 80 kPa.ThePACthicknessincreased 50% with twice coating time. However the resistanceonly increased 13%. It was attributed to the large PAC particle size and loose packing structure of dynamic membrane.
Tocombine coagulationoperations withsubmergedfiltration processes, either theuseof 0.45μm PVDFmembrane or PAC dynamic membrane, the flux was improved.The flux of seawaterwithcoagulant increased with increasing transmembranepressure.However, theflux declineddramatically at the beginning of filtration, the major resistance sources werethose organic materials fouling on themembranes.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, COD,DOC,turbidityand concentration of humic acid, for each operation was measured.The permeate quality met the requirement of RO feed.On the other hand,compared to directly add PAC into suspensionto adsorb organic material, the use of PAC dynamic membrane significantly reduce the cost of PAC.Beside, the submerged system only cost 8% of pre-coating time by cross-flow system.
| Identifer | oai:union.ndltd.org:TW/104TKU05063007 |
| Date | January 2016 |
| Creators | Ya-Lun Cai, 蔡雅倫 |
| Contributors | 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 | 120 |
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