本研究以偏光板廠實際操作，記錄偏光板製程中「TAC膜表面處理程序」生產時，各水洗槽用水及排放水量，並分析各排放水水質，再依各項數據對不同的回收再利用及節水方案，進行最佳模式評估。研究結果顯示，偏光板廠「TAC膜表面處理程序」製程排放水，排放至廢水處理時，只需調整pH值即可直接放流，若比對純水製造系統各單元，這股排放水水質是符合活性碳塔用水標準的，在方案一中將製程排放水從管末收集，回收至純水製造程序中的活性碳塔，可再製成純水，以供全廠各製程使用，以TAC膜表面處理程序總用水量計算回收效率為36.3%。在方案二中進一步分析TAC膜表面處理程序用水現況，發現純水經儲存、輸送到使用，在水質導電度上，已與RO產水水質相當。若將方案一中回收至純水系統的這股排放水，在產線進行集收，並以獨立RO系統再製純水，直接補充至TAC膜表面處理程序，成小循環的模式再使用，並減少廢水排放量，其所回收的水量為「TAC膜表面處理程序」總用水量的34.85%，並減少了純水製造流程中活性碳塔及陰陽離子混床的操作成本。最後的方案三則參照電鍍業中廣為使用的「逆流清洗」技術，進行線上清洗水直接逆流再使用，可使純水補充量直接下降50%，相當於回收「TAC膜表面處理程序」總用水量的50%，且不需設備處理及耗材費用。Great amount of water is used in the washing process in polarized plate industry. The objective of this work is to reduce the water consumption by modifying the washing processes. Three modifications were proposed for the TAC film process. The water consumption and the solution pH and conductivity were recorded to evaluate the effectiveness, the cost, and the flexibility of the modifications. Method 1 recycled the wastewater by the activated carbon tower used in the pure water system, which can recycle 36.3% of the wastewater. However, by doing so, the activated carbon tower cannot treat more raw water. It was also found that the quality of the wastewater in TAC film washing was similar to that of water treated by reverse osmosis (RO). Modification 2 recycled the wastewater from the TA film washing by RO, which can recycle 34.9% water used in this process. Besides, it also reduce the cost for activated carbon tower and ion exchange in water purification. Last, the modification is to reverse the washing process from the less dirty tank to the more dirty tank, which can reduce the water consumption up to 50%. Besides, no capital cost and maintenance fee were required.
