以電化薄膜程序自錯合離子溶液中回收螯合劑及金屬

Recovery of Chelating Agents and Metals from Complexed Ion Solutions Using an Electrochemical Membrane Process

林麗君(Li-chun lin)

指導教授 ： 莊瑞鑫

元智大學/工程學院/化學工程與材料科學學系/碩士(1997年)

摘要

本論文的研究目的在於提供將錯合離子溶液濃縮至何種程度時，以電化學
薄膜法來回收金屬與螯合劑，可得最佳的回收率與電流效率。研究的方法
為以模擬之金屬螯合劑溶液作為對象，使用自製的直流電源供應器電解金
屬螯合物，在不同的攪拌速度、陽離子膜、電流密度、工作電極、反應槽
的型式、錯合離子溶液之濃度與pH值、陽極液之組成及金屬與螯合劑之種
類等條件下，測試金屬與螯合劑之回收率和電流效率的情形。
由研究結果得知，不論是電解Cu-EDTA或Cu-NTA，極限電流密度為110A/m2，
最佳的pH在2.2附近。若在相同的時間與定電流密度操作下，將Cu-EDTA的
濃度提高，電流效率及Cu與EDTA的回收量也會提高，最佳的電解濃度為
0.02 M。此外，由於Cu-EDTA的導電度很差，因此使用導電度較高的陽離子
膜、在陽極液中添加高濃度的強電解質及提高攪拌速率等，均能提高電流
效率及Cu與EDTA的回收率。

關鍵字

回收 ； 螯合劑 ； 金屬 ； 電化薄膜程序 ； 錯合離子溶液

並列摘要

The objective of this research is to provide an electrochemical membrane method to recover the metal and chelating reagent from the complex solutions. The tested solutions were placed in the electrolytic cell, electrolyzed under various stirring rates, cationic exchange membranes, current densities, working electrodes, types of reactor, concentrations of complex solutions and pH values, compositions of catholytes , and types of metals and chelating reagents, then recorded the recovery and current density of tested metals and chelating agents.
From the results, we concluded that no matter whether the complex is Cu-EDTA or Cu-NTA, the limiting current density is 139 A/m2 and the optimum pH value is about 2.2. In addition, when electrolyses were performed under the same time period and current density, if the concentrations of Cu-EDTA solutions were increased, the current efficiency and recovery of Cu and EDTA would be increased accordingly, and the optimum concentration is 0.02 M. Besides, since the electrical conductivity of Cu-EDTA solutions was very poor, we had chosen cationic exchange membrane with high conductivity, added concentrated electrolytic solutions and raised the stirring rate to increase the current efficiency and recovery of Cu and EDTA.

並列關鍵字

Recovery ； Chelating agents ； Electrochemical membrane process ； Complexed ion solution

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