| 摘要: | 台灣因地形地貌特殊且陡峭，又加上山坡地過度開發，導致集水區水土保持不良。颱風或暴雨季節過後，產生的高濁原水問題長期影響國人飲用水及工業用水使用。現今水廠處理高濁度原水之方式為添加高劑量的混凝劑，但此方法會衍生出大量的污泥餅，使得後續處理污泥成本增加。
本研究為探討沈浸式中空纖維微過濾膜，作為處理高濁度原水之可行性。為確保利用沈浸式中空纖維微過濾膜應用於高原水濁度的可行性，本研究利用實驗設計方法，選擇影響薄膜阻塞的因子如：曝氣強度、混凝劑、停歇時間、洩流濃縮液比率及濁度。依據因子設定並觀察結果臨界通量，篩選出重要因子，接下來利用篩選出之因子做反應曲面法（Response Surface Methodology, RSM）結合中心混層設計（Central Composite Design, CCD）找尋最適點之位置，並製作出反應曲面分析圖，探討減緩薄膜阻塞的可能性。
本研究中，添加混凝劑可增加濁度顆粒尺寸，使得濁度顆粒具有相當良好的沉降性，濁度可大幅減少，但添加多於的混凝劑劑量並不能使所得之臨界通量提高。
經配適二次迴歸模型運算過後可得知最適值位於，固定添加混凝劑之下，當洩流濃縮液之比例為5 % 時，且濁度為5000 NTU及停歇時間3分鐘，曝氣量為5 L min-1時，透過模式可預測出本實驗膜組操作的之臨界通量為112.97 LMH。
Due to steep slope, special geographical features, over-developed hillside, and improper soil water conservation of catchments area, events of high turbid water in drinking water supply are happen frequently during typhoon or rainy season, causing shortage for drinking water and industry water usage. To tackle the situation of high turbid water, a common practice in water treatment plants is to add an elevated dose of coagulant. However, a huge amount of sludge is produced and as a result skyrocketing cost has to be added for sludge handling.
This research is to evaluate the practicability of dealing with high turbidity water using submerged hollow-fiber microfiltration (MF) with factors such as Aeration, Coagulation, Relaxation Time, Bleeding and Turbidity being studied by Factorial Design. Based on critical flux result, the most significant factors are selected. Furthermore, the selected factors are use through Response Surface Methodology (RSM) and Central Composite Design (CCD). At the end, seeking the optimum and making the graph is for researching possibility of lowering microfiltration block.
In this study, coagulant addition can enlarge size of particle size and such particle further makes a great sedimentation. However, adding extra coagulant is not able to raise critical flux result, 3 mg L-1 as Al is the best option in this study.
After adding a certain amount of coagulant and exercising under the condition of 5% bleeding ratio, 5000 NTU turbidity, 3 minute relaxation time and 5 L min-1 aeration, membrane gets critical flux, 112.97 LMH, which is predicted as the critical flux value through this model operation. |
