| Abstract: | 近年，我國半導體製造業已迅速提升至全球市佔第一，然而，隨著銅製程技術的興起與晶圓尺寸的提升，半導體業與環境面臨了含銅重金屬廢水污染和高耗水量之衝擊。傳統化學混凝沉澱處理，其化學品的高消耗量與產生之重金屬污泥。隨著環保意識與技術的提升和高原物料成本，資源再利用化已成為各界關注的議題。 本研究結合超濾（UF）和電透析（ED）薄膜處理技術資源化銅製程化學機械研磨（Copper-Chemical Mechanical Polishing, Cu-CMP）廢液。試驗中，利用掃流式(cross flow)超過濾薄膜系統去除奈米級SiO2研磨砥粒，並以批次式電透析系統回收過濾液中的銅離子，而藉由不同操作參數，分析產水通量、產水水質與最佳化之操作條件，探討水資源和銅金屬回收的可行性。實驗利用polyvinylidenefluoride（PVDF）材質之UF薄膜、商用離子交換膜（SKS-C ; SKS-A）以及石墨電極進行試驗，以不同參數：SiO2濃度500, 1000, 1500, 2000 mgL-1，〔Cu2 +〕為10, 25, 50, 120, 200, 500 mgL-1，pH值3, 4, 5和電壓梯度0.5, 1.5, 2.5 Vcm – 1進行探討。研究中得知UF系統可以有效地分離奈米粒子，其去除率達99.7 ％，而當ED程序以批次反應處理過濾液中的銅離子時，操作條件為電壓梯度1.5 Vcm- 1，反應時間3小時，則銅離子去除效率可達到 99.3 ％以上。並可再以酸劑萃取陽離子交換膜中所吸附之銅離子約93.5 %。 ED薄膜系統回收Cu-CMP廢液為一項新興的技術，可有效的避免其他處理系統所面臨的問題，如薄膜積垢，離子交換樹脂阻塞和批次反應槽長菌等。而藉由結合UF+ED薄膜系統處理Cu-CMP廢液，可有效率且簡易地達到放流水標準（3 mgL- 1），並且利用酸劑萃取的方式，達到銅金屬回收再利用的可行性。
Since the development of copper manufacturing technology in 1997, the environmental impact of copper contamination and higher water consumption are serious challenges facing for the IC and Semiconductor industries nowadays. Traditional wastewater treatments processes typically require high chemical consumption and generate heavy metal sludge volume. With the rising environmental awareness and high raw material cost, the reclamation processes have come into public attention.This research focuses on the efficiency of an integrated water reclaim system with Ultrafiltration (UF) and Electrodialysis (ED) for treatment and reclamation of Copper- Chemical Mechanical Polishing(Cu-CMP) wastewater. In this work, the permeate flux for the ultrafiltration membrane are investigated using artificial solutions containing nano-scale silica particles and Cu ions. Using different operating parameters we studied the separation efficiency, produced water quality and the optimal conditions applied to SiO2 and Cu raw material recovery. Experiments are conducted using commercial polyvinylidenefluoride (PVDF) membrane, ion exchange membranes (SKS-C；SKS-A), and graphite electrodes in both batch and continuous operations with three parameters: concentration (〔SiO2〕: 500, 1000, 1500, 2000 mgL-1;〔Cu2+〕=10, 25, 50, 120, 200, 500 mgL-1), pH (3, 4, 5) and voltage gradient (0.5, 1.5, 2.5 Vcm-1). The UF membrane system effectively separate the particles from the solution with a rejection rate over 99.7 %, then the ED process reclaim Cu ions from permeate solution. The removal efficiency of copper can reach above 99.3 %, when the operating conditions in the well-stirred batch reaction process are constant voltage gradient 1.5 Vcm-1 and reaction time 3 hr. Results from the desorption experiment presented the release amount of 93.5 % of copper from ion-exchanger membrane.The improvement of adsorption efficiency by the modified ED system is an emerging technique for recycling heavy metal from Cu-CMP wastewater because it is capable to attenuate problems such as membrane fouling, block of ion exchange resin, and microbial activities in a batch reactor. The combination of membrane systems treat the Cu-CMP wastewater to the level that easily meets the Taiwan EPA’s effluent regulations (3 mgL-1). With efficient desorbing solution, from this study presents the feasibility for removal and recovery of copper from wastewater. |
