以高效能P型半導體電極濾膜反應系統去除水溶液中微量有機物

Abstract

高級氧化處理(Advanced oxidation processes, AOPs)已被廣泛應用於環境污染物之降解，其中，電化學氧化法因可快速降解有機及無機污染物，於近年漸受各界重視。鑽石電極因具有較高之過電子勢能(Overpotential)可產氧(Oxygen evolution)，並進一步轉換成氫氧自由基使污染物完全降解；但鑽石電極雖具諸多優點，卻往往因成本過高而無法於環境上廣泛應用；因此，本研究期以電極基材複合類鑽碳、奈米碳管等類鑽之材料，並以半導體摻雜(Doping)方式進行P型半導體陽極之開發，如此可大幅降低成本，進而將所開發之P型半導體電極與無機濾膜結合。所製備之P型半導體電極材料及電極濾膜將以SEM、TEM、XRD、UV/Vis Spectrometer及循環伏安法分析其特性，並以偶氮染料(Azo-dye)做為半導體電極薄膜效能評估之典型有機污染物，利用自由基氧化污染物之機制進行偶氮染料脫色及降解，並建立相關資料及半導體電極薄膜反應器系統，以供後續研究與應用之參考。研究內容包含: (1) P型半導體電極材料之開發、(2) P型半導體電極晶型結構及雜質濃度之效能評估、(3) 結合P型半導體材料與無機濾膜之可行性評估、(4)以P型半導體電極薄膜處理污染物之機制及自由基濃度相關性探討及(5)建立自動化P型半導體電極薄膜系統及系統最佳化之研究，期能將此研究成果提供後續研究之參考，並將此技術應用於高科技廢水中微量有機物之處理及純水之再生程序。

Advanced oxidation processes (AOPs) have been extensively used in the degradation of pollutants. In recent years, several works have been conducted to effectively degrade organic pollutants using electrochemical oxidation processes (EOP). Diamond electrodes produce oxygen which is subsequently converted to OH radicals due to its high over-potential. Thereafter, the pollutants can be oxidized by OH radicals. Although there are many advantages for diamond electrode, the cost is too high to apply in wastewater treatment practices. Therefore, the aim of this study is to coat diamond-like carbon (DLC) and carbon nano-tube (CNT) on the surface of electrodes doped with boron as a P-type semiconductor electrode. The cost-competitiveness could be expected. Furthermore, the novel P-type semiconductor electrode is combined with inorganic membrane to develop a novel P-type membrane. The characteristics of the P-type semiconductor electrode and the P-type membrane will be examined by SEM, TEM, XRD, UV-Vis Spectrometer as well as Cyclic Voltammetry. The electrochemical oxidative effect of the P-type membrane will be evaluated by degradation of an Azo-dye, Acid-yellow 36 (AY-36). The scope of this study includes: (1) synthesis of the P-type semiconductor electrode, (2) effect of crystal phase and impurity concentration in the P-type semiconductor electrode on electrochemical efficiency, (3) feasibility of the P-type membrane, (4) mechanisms of OH radical formed by the P-type membrane and (5) optimization of a pilot-scale P-type membrane reactor automatically. The objective of this study is to develop an applicable P-type membrane reactor system with high efficient removal for the trace organics in the wastewater reclamation and pure water production processes.