本研究旨在了解碳氣凝膠電極所建立之電容系統，在競爭吸附情況時，電容去離子化的情形。實驗使用重金屬溶液為氯化鉻、氯化銅及氯化鉛，初始濃度皆為0.5 毫莫爾濃度，在多金屬系統的競爭組合為兩金屬的氯化銅及氯化鉛、氯化銅及氯化鉻與三金屬的氯化鉻、氯化銅及氯化鉛。單一金屬系統為比較離子半徑及價數不同在去除重金屬離子的能力，而多金屬系統則為研究不同電壓及競爭情況下去除的情況。 在單一金屬系統去除效率方面，金屬在相同價數情況下，銅的去除效率較鉛為高，是由於銅的離子半徑較小。而在不同價數的比較中，銅的去除效率也較鉻為高，是由於鉻價數較大，使得電容器僅能夠容納較少的鉻。在兩金屬組合的氯化銅及氯化鉛競爭下，鉛的去除效率較佳，氯化銅及氯化鉻組合中，銅的去除效率較佳。而在鉻、銅及鉛三金屬競爭情況下為去除效率為銅大於鉻，再大於鉛。 電壓可以影響兩金屬組合中的氯化銅與氯化鉛的去除能力，然而在有鉻金屬存在的狀況下，電壓並不能影響其對金屬的去除能力，且被吸附的金屬並不能隨著解除電壓而釋放出來。而在比較鉻、銅及鉛三金屬競爭的能力，鉻為三者中最佳，其次為鉛最後為銅。 The objective of this work was to understand the competitive electrosorption of heavy metal by capatative deionization (CDI) equipped with carbon aerogel. Single-metal-ion system was studied to understand the effects of ionic radius and valence on the removal of heavy metal ions by CDI. Electrosorption of multi-metal-ion was conducted to investigate the effects of the applied voltage and competitive electrosorption of Pb2+/Cu2+, Cu2+/Cr3+, and Pb2+/Cu2+/Cr3+. The initial concentrations of all three heavy metals used in this work (i.e., CrCl3, CuCl2, and PbCl2) were 0.5 mM in either single-metal-ion or multi-metal-ion systems. The adsorption of Cu2+ was better than that of Pb2+ because the electrosorption efficiency increased with decreasing ionic radius when metal ions have the same valence. The adsorption of Cr3+ was less than that of Cu2+ because Cr3+ had higher charge and the capacitor could hold less Cr3+. For Pb2+ / Cu2+ adsorption, the adsorption of Pb2+ was better than that of Cu2+. For electrosorption of Cu2+ / Cr3+, the adsorption of Cu2+ was better than that of Cr3+. For electrosorption of Pb2+ / Cu2+ / Cr3+, the order of the adsorption amount and rate from the largest and fastest was Cu2+, Cr3+, and Pb2+. The adsorption of Cr3+ was the most competitive, followed by the adsorption of Pb2+ and, then Cu2+. The applied voltage showed effects on the electrosorption Pb2+ / Cu2+, however, showed no effects on the experiments with Cr3+. When Cr3+ was in the system, Cr3+ helped metal ions be fixed on the carbon aerogel after the removal of the applied voltage.