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。由於電雙層重疊問題會造成離子無法微小孔洞，又多數電極材料之孔洞均質性不佳的問題，使得不論在CDI電雙層吸附基礎學理、模式推估，以及實際水處理應用上受到限制。因此本計畫擬利用靜電紡絲技術並搭配孔洞控制，製備均勻度較佳之碳纖維電極，應用於CDI系統。第一年將以選定最佳製備參數為主，將所得到的碳纖維電極進行CDI系統處理NaCl，瞭解所製備電極之基本效能。第二年將以提升去離子能力為目標，製備金屬氧化物/碳纖維複合電極，除分析電極效能外，亦將進行有機物對CDI系統去離子之初步探討。實驗結果將進行吸附動力、等溫吸附、以及電雙層模式擬合，以其運用孔洞性質較佳的電極，能對CDI系統之反應基理有進一步的瞭解。 ;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 and thus to removal 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 problem. Therefore, CDI, which was originally developed to deionize sea and brackish waters, has been considered a promising technology for water reclamation. The overlapping of double layer may prohibit the transport of ions into pores. The porous characteristics of current carbonaceous electrodes limit the theoretical investigation and application in water/wastewater treatment of CDI. Thus, it is proposed to fabricate carbonaceous fiber as CDI electrodes via electrospinning. The main objective of the first year is to determine the optimal preparation conditions of the carbonaceous fiber. The performance of the prepared electrode in CDI will also be evaluated. In the second year, metal oxide/carbonaceous fiber composite will be prepared in order to enhance the adsorption of ions. The influences of organic compounds on the deionization will also be investigated. The experimental results will be modeled by adsorption kinetics, isotherms, double-layer Donnan equations. It is proposed that by using electrodes with better porous characteristics, the adsorption and transport of ions in CDI could be better understood.
