Photoelectrocatalytic Oxidation of CuII鈥揈DTA at the TiO2 Electrode and Simultaneous Recovery of CuII by Electrodeposition

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• 作者：Xu Zhao ; Libao Guo ; Baofeng Zhang ; Huijuan Liu ; Jiuhui Qu
• 刊名：Environmental Science & Technology (ES&T)
• 出版年：2013
• 出版时间：May 7, 2013
• 年：2013
• 卷：47
• 期：9
• 页码：4480-4488
• 全文大小：508K
• 年卷期：v.47,no.9(May 7, 2013)
• ISSN：1520-5851

文摘

The simultaneous decomplexation of Cu鈥揈DTA and electrodeposition recovery of Cu²⁺ ions was attempted in a photoelectrocatalytic (PEC) system using TiO₂/Ti as the anode and stainless steel as the cathode. At a current density of 0.5 mA/cm², removal efficiencies of 0.05 mM Cu鈥揈DTA by photocatalysis, electrooxidation, and PEC processes were determined to be 15, 43, and 72% at 3 h, respectively. Recovery percentages of Cu²⁺ ions were determined to be 10, 33, and 67%, respectively. These results indicated that a synergetic effect in the decomplexation of Cu鈥揈DTA and recovery of Cu²⁺ ions occurred in the PEC process, which favored acid conditions and increased with the current densities. The removal of Cu鈥揈DTA and Cu²⁺ ions can be described by a pseudo-first-order kinetics model. Ca²⁺ ions significantly increase the removal of Cu鈥揈DTA and recovery of Cu²⁺ ions. Intermediates, including Cu鈥揘TA, Cu鈥揈DDA, acetic acid, formic acid, and oxalic acid, were identified, and a decomplexation pathway of Cu鈥揈DTA was proposed. The Cu鈥揈DTA decomplexation at the anode via oxidation of hydroxyl radicals was revealed. On the basis of X-ray photoelectron spectra analysis, a reduction pathway of Cu²⁺ ions at the cathode was discussed. The present study may provide a promising alternative for destruction of the metal complex and recovery of metal ions.