水資源回收再利用，以及對於環境水體品質與放流水的水質的要求,如何提昇處理技術以符合日趨嚴格的水質標準，是一重要課題, 同時以永續的觀點，水處理技術的開發希望降低處理耗能。電容去離子技術(capacitive deionization, CDI)主要運用多孔導電材料，將水中離子捕捉在電容中，達到水質淨化目標，並可以在去除電場(放電)後，再將所捕捉的離子釋放，相較薄膜系統，尤於沒有滲透壓的問題不需要提供大量的能量，也沒有膜阻塞的問題，因此近年來也逐漸被探討處理水中其它物質的可能。本計畫擬利用電容去離子系統，進行氟系廢水與氨氮廢水處理，本團隊已初步利用電容去離子系統對HF模擬廢水進行處理, 效果良好. 因此希冀藉由本計畫延續後續工作, 如探討氟系廢水中常見的其他酸根離子對於除氟成效之影響。同時，光電業在蝕刻過程中，除了HF外，亦常使用NH4F, 但NH4+是否會在系統中因操作pH或是其他氧化劑的存在發生氧化還原等反應，進而影響除氟之成效，需要瞭解後才可對此技術後續開發與改良有所基礎。因此也將針對NH4F 模擬廢水的電容去離子處理，並將藉由分析氮的不同物種，探究氨氮在CDI 的過程中，可能發生的其它反應，以及系統之反應動力學。並將自光電業採集廢水水樣進行實場水樣試驗。本研究成果可瞭解CDI 系統去除氟系廢水之能力，並做為後續提升電容子去離子系統處理氟系廢水技術開發之基礎。 ;For water reclamation and for better water quality, development of advanced wastewater treatment technologies has been an important issue. Capacitive deionization (CDI) captures ions in the porous conductive materials in an electric field and thus remove ions from water. The captured ions can be released once the system is discharged. Compare to membrane filtration, CDI does not require large power consumption to overcome osmotic pressure and does not have fouling problems. Therefore, CDI, which was originally developed to deionize seawater and brackish waters, has also been found applications in wastewater treatment. We have studied the removal of fluoride from HF by CDI and found good removal efficiency. As there are always other anions in the fluoride wastewater, we would like to continue our study on the treatment of fluoride by CDI, especially on the effects of other anions on the removal of fluoride. Also, NH4F is also commonly used in the semiconductor industry. The oxidation/reduction and other reactions of NH3+ may introduce adsorption competition with fluoride or affect the removal of fluoride in CDI. Thus, in this work, the speciation of nitrogen in CDI will also be investigated. The reaction kinetics and removal of fluoride from real semiconductor wastewater will also be examined. The results of this work will provide knowledge of the performance of CDI on removal of fluoride and the development of water reclamation technology from fluoride wastewater via CDI.
