本篇研究的目的在於應用微流體系統的優點，利用微小系統反應靈敏且所需實驗時程較短的特性，設計整合奈米過濾(NF)薄膜於一晶片式的膜組(membrane module)上，以觀察、分析硫酸鈣無機鹽類於薄膜表面結垢阻塞的型態及對過濾效率之影響。本研究參考平板狀膜組(plate and frame)架構，採用直接端點過濾法(dead-end filtrition)，設計出操作簡單的晶片式膜組過濾系統，設計並開發出一微型化晶片式膜組，利用奈米濾膜的篩網作用以及離子電荷作用進行分離，能簡單且快速獲得分析所需之無機鹽類結垢樣本，加上即時壓力值、滲透流通量遞減趨勢、濾膜表面電性量測，以及膜面即時影像觀測等作為，本系統可以簡單、迅速的判斷濾膜表面無機鹽類結垢機制的影響，並獲得明確的即時過濾參數。
本研究發現，即時過濾壓力值在高低不同過濾流率下均可以將壓力曲線分為三個不同過濾階段來探討。第一個部分是過濾開始時的線性上升區段，此區段主要效應為濃度極化與成核現象的產生，所以進給流率與過濾流率間呈現一穩定的關係。第二部分是受到膜面結晶生成的影響，造成壓力上升的趨勢。然而高低過濾流率會影響結晶生成的速率，於是在較低過濾流率下(20 L/m2･hr ~ 28 L/m2･hr)有一段壓力緩慢平穩上升的狀態。而在高過濾流率的條件下(32 L/m2･hr ~ 40 L/m2･hr)則明顯縮短了壓力緩升區段的時間。第三部分為結晶持續累積，而過濾阻抗迅速增加，造成壓力分佈急遽上升的趨勢。
本研究並整合膜面電極設計，進行濾膜表面的即時電性量測測。由無因次化電導度與即時壓力分析可以發現，在濃度極化以及成核階段，濾膜表面壓力與測得的無因次化電導度曲線具有明顯之相關性。在濃度極化過程其電導度與壓力呈現同步線性上升的趨勢，但濾膜表面之電導度將到達一極大值後些微下降，此乃過飽和溶液開始成核結晶所造成之電導度下降，隨後便進入一動態平衡之階段，結晶開始穩定成長。此乃文獻中首次得以即時觀測到濾膜表面結晶動力學之結果。此外，由膜面即時影像觀測可以發現，過濾進行時，肉眼可見的體結晶(bulk crystal)比面結晶(surface crystal)早出現，此亦目前文獻報導中未曾明確證明之處。
本研究發展一易於整合線上即時觀察的晶片式膜組，其不需經由複雜且專業的水質檢測指數與圖表資料以分析濾膜表面過濾狀況。不僅可以簡化判斷濾膜表面的狀況，並可以電性量測訊號的結果，提供即時與明確的濾膜表面資訊，為一具有發展潛力的水處理應用技術。

This study develops and demonstrates a microfluidic module for investigating the mechanism of inorganic fouling caused by the precipitation of calcium sulfate (CaSO4) on nanofiltration membranes. The developed microfluidic module enables sensitive system responses, rapid detection and real time observation of inorganic fouling commonly encountered in water treatment industries. For this development, CaSO4 is selected as the model salt due to its unique fouling characteristics. The effect of the operating conditions, such as pressure and permeate flux, was on the fouling behavior is investigated. A plate-frame type microfluidic chip was fabricated and employed in a dead-end filtration mode for constant-flux fouling experiments. The nanofiltration chip module has a dimension of 50 mm × 25 mm × 12 mm. It is consisted of a polymeric nanofilter, a pressure acquisition unit, a C.C.D., and micro electrodes on the nanofilter for investigating the relationships among trans-membrane pressure, conductivity on membrane surface and permeate fluxes. With the microfluidic system, real-time concentration polarization, bulk nucleation of CaSO4 and surface crystal accumulation were observed in terms of the variations of pressure and conductivity on membrane surface, which were verified with scanning electron micrographs to confirm the corresponding fouling stage. It is found that membrane surface conductivity increases with trans-membrane pressure before bulk crystallization of CaSO4, then slightly decreases after the formation of bulk nuclei due to the removal of solute in the aqueous phase. The conductivity remains relatively constant during cake formation stage while trans-membrane pressure steadily increases. This study successfully integrates microfluidic technology with pressure and electrical measurements for detecting the dynamic transition during CaSO4 fouling, and reports for the first time the experimental measurement of the initiation of inorganic cake formation.

目錄………………………….……………………………..…………….I
圖目錄…………………………………………………………………..IV
表目錄……………………………………………………………….. ..VII
中文摘要……………………………………………………………...VIII
Abstract………………………………………………………..………...X
致謝.........................................................................................................XII

第一章、 緒論
1.1 前言………………………………………………………………….1
1.2 濾膜與膜分離技術簡介…………………………………………….3
1.2.1濾膜簡介………………………………………………………3
1.2.2分離技術簡介…………………………………………………5
1.3 奈米濾膜…………………………………………………………….9
1.4 研究目的與動機…………………………………………………...12
1.5 文獻回顧…………………………………………………………...13
1.5.1濾膜的基本特性與應用……………………………………..13
1.5.2影響濾膜性能的因素………………………………………..18
1.5.3數學模式與理論探討………………………………………..25
1.6 研究架構…………………………………………………………...29

第二章、 過濾原理與晶片式水處理系統設計
2.1濾膜過濾原理……………………………………………………….31
2.1.1篩濾作用與靜電效應…………………………………….......32
2.1.2過濾模式…………………………………...............................35

2.2晶片式設計概念…………………………………………………….37
2.2.1 一般水處理系統………………………………………….....38
2.2.2晶片式膜組設計……………………………………………..41

第三章、 實驗系統架設與晶片製造
3.1 實驗系統架設與設備……………………………………………...44
3.2晶片膜組製造與實驗流程………………………………………….48
3.2.1 晶片膜組製作……………………………………………….48
3.2.2 實驗流程…………………………………………………….49
第四章、 實驗結果與討論
4.1 濾膜性能……………………….…………………………………..53
4.1.1滲透流通量與膜面淨阻抗的關係…………………………..54
4.1.2回復率與鹽類阻擋率百分比………………………………..55
4.1.3滲透流通量與結晶重量的關係……………………………..56
4.1.4滲透流通量與濃度極化的關係……………………………..59
4.2進給流率的比較…………………………………............................60
4.2.1不同進給流率下的壓力分佈………………………………..61
4.2.2不同進給流率下的滲透流通量……………………………..64
4.3微小電極與電性偵測………………………………………………65
4.3.1微電極電導度理論…………………………………………..66
4.3.2電導度與濃度極化…………………………………………..71
4.4膜面結晶觀察……………………………………………………….72

第五章、 結論與未來展望
5.1 結論………………….............…......................................................80
5.2 未來展望…………….............…......................................................81
參考文獻…………….............….............................................................83
自述……………………………………………………………………..87

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