以電混凝法處理化學機械研磨廢液與研磨液中顆粒凝聚行為之特性研究

Electrocoagulation on CMP Wastewater Treatment and The Behavior of Particle Coagulation

劉奕宏(Yi-Hung Liu)

指導教授 ： 顏溪成

國立臺灣大學/工學院/化學工程學研究所/碩士(2005年)

https://doi.org/10.6342/NTU.2005.10045

摘要

本研究主要分為五個部分來探討化學機械研磨廢液的奈米顆粒去除：
第一部分為顆粒表面性質與凝聚行為受到不同溶液環境的變化；第二部分為透過DLVO理論來模擬顆粒間的作用行為與其理論驗證；第三部分電混凝過程中的處理效率研究與處理過程當中必要性參數之影響；第四部份為探討電混凝過程中相關的反應行為，與反應機制的模擬；第五部分為運用實驗規劃的過程對於奈米顆粒移除決定最佳參數以期達到最適化的處理效果。
實驗結果發現在化學機械研磨液的奈米顆粒移除上，對於濃度較高的研磨廢液而言，在電混凝反應前氯化鎂的添加可以先降低顆粒濃度以避免因濃度過高造成的電混凝電級鈍化現象，同時其氯離子的存在也可以提升後續的電混凝處理效率。根據顆粒凝聚相關實驗的結果，在化學機械研磨液之奈米顆粒凝聚行為比理論模式的估算顯得更為複雜，因此在處理上所需要注意的參數調整與控制將顯的更為重要。
對於電混凝的處理效益而言，也經由實驗發現，其過程中之曝氣，電流強度控制，混凝完後的pH值調整式顯的較為重要的，同時根據調整好的參數可以觀察到在顆粒移除可以達到約99％的處理效益。並藉由反應機制的模擬過程，探討其反應程序為第一部分的膠體奈米顆粒與鐵離子的主要反應步驟，待顆粒越過凝聚的能量障礙後再進行第二部分快速凝聚步驟。最後在根據實驗設計的法則預測本實驗所需要控制的顯著因子於電流密度大小為0.0455A/cm2，通電時間為11.3分鐘，電混凝完後之pH值調整為5~6之間會有最佳的處理效果。

關鍵字

化學機械研磨廢液 ； 電混凝 ； 顆粒間的作用行為 ； 顆粒移除

並列摘要

This thesis on separation between nano-particles and water in CMP wastewater by electrocoagulation has been mainly studied in five parts. The surface properties and behavior on coagulation of particles changing with various conditions were investigated in the first part of the study. Particle’s interactions were simulated and verified by DLVO modeling in the second part. Treatment efficiency affected by some important parameters and kinetic reaction modeling in the electrcoagulation process were investigated in the third and the forth part respectively. Optimization in the electrocoagulation process by experimental design was investigated in the final part of the study.
According to the experimental results, I prefer to add MgCl2 for higher wastewater concentration to avoid passivation in the latter electrocoagulation(EC) process in CMP wastewater treatment. In addition, the left chloride anion was beneficial in the latter EC process. The behavior on coagulation between particles in CMP wastewater is more complicated than assessed by DLVO theory and it is more important on parameters controlling in the EC process.
It was found aeration, current density, and pH controlling after EC treatment are necessary in the EC process and almost 99％ of particle removal efficiency was achieved by proper conditions in the treatment. It was also found particles and Fe3+ ions react in the first main reaction and then particles coagulate together rapidly in the second reaction by the kinetic modeling. Finally, the optimum parameters were determined by experimental design and the optimum parameters in the EC treatment including : 0.0455 A/cm2, 11.3 minutes during EC treatment, and pH controlling between 5~6 after EC treatment.

並列關鍵字

CMP wastewater ； electrocoagulation ； particle removal

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