碩士 / 元智大學 / 化學工程與材料科學學系 / 98 / This research utilizes a hybrid process of membrane microfiltration and ultrafiltration effect to deal with the wastewater of cellulosic ethanol. The best operating conditions for this purpose were determined. Filtration experiments were conducted by dead-end system, under various operating conditions to discuss the flux and rejection (%).To improve fouling phenomenon, the cross-flow mode is used to membrane filtration. The membrane module was repeatedly washed in the cross-flow system. The appropriate membrane is investigated in MBRs.
In dead-end system, the ER membrane has the best effect of filtration for the failured fermentation wastewater.The rejection is achieved 27 % in a short time when the operating pressure is 68.9 kPa. Furthermore, flux is within the MBRs range. Treating with aeration process followed by 30~40 % removal of COD results in rejection promotion for successful fermentation wasteater. When flux of PVDF membrane is within MBRs range, the best rejection of PVDF membranes is 47.2%. The MFI (Modified fouling index) were used to analyze flux behavior. It was shown that the flux decline was due to solute concentration polarization and fouling.
In cross-flow system, the lower initial flux of PVDF membrane is within MBRs range, and the rejection is 61%. Backflushing with pH 13 NaOH shows a better effect. Initial flux remains 70 dm3/hr-m2 under 68.9 kPa with PVDF membrane. Different filtration time and washing time ware used as a means to matain the permeate flux with 55~65 dm3/hr-m2 and 25~40 dm3/hr-m2. PVDF membrane is durable, and its flux can be applicate to MBRs. Therefore, these results clearly indicate that PVDF membrane is more sutible for MBRs.
| Identifer | oai:union.ndltd.org:TW/098YZU05063084 |
| Date | January 2010 |
| Creators | Wei-Zhi Hong, 洪偉致 |
| Contributors | 莊瑞鑫 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 109 |
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