Self-Enhanced Decomplexation of Cu-Organic Complexes and Cu Recovery from Wastewaters Using an Electrochemical Membrane Filtration System.
Self-Enhanced Decomplexation of Cu-Organic Complexes and Cu Recovery from Wastewaters Using an Electrochemical Membrane Filtration System.
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DOI：
10.1021/acs.est.0c05554
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发表时间：
2020-10
影响因子：
11.4
通讯作者：
Jiayi Li;Jinxing Ma;Ruobin Dai;Xueye Wang;Mei Chen;T. Waite;Zhiwei Wang
中科院分区：
文献类型：
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作者：
Jiayi Li;Jinxing Ma;Ruobin Dai;Xueye Wang;Mei Chen;T. Waite;Zhiwei Wang
工业废水中的重金属通常以稳定的金属有机络合物的形式存在，其具有成本效益的处理仍然是一个重大挑战。在此，开发了一种自增强的解络合方案，使用电化学膜过滤（EMF）系统进行有效的解络合和铜回收。以Cu-EDTA为模型污染物，在3V的槽电压下，体系对Cu-EDTA络合物的解络合率为81.5%，铜的回收率为72.4%。阳极产生的·OH首先进攻Cu-EDTA，生成中间产物Cu-有机络合物，后者与阴极溶解氧还原生成的H2 O2发生催化反应，引发链状自络合反应，生成Cu-有机络合物。增强了EMF系统的解复杂性。解络合的Cu产物在阴极膜表面被进一步还原或沉淀，从而实现有效的Cu回收。通过清除H_2O_2（不包括自增强解络），解络速率从8.8 × 10 ~（-1）h ~（-1）降至4.1 × 10 ~（-1）h ~（-1），证实了自增强解络在该体系中的重要作用。该系统的能量效率对于Cu-EDTA解络合为93.5g kWh-1，对于Cu回收为15.0g kWh-1，这远高于先前文献中报道的（即，7.5 g kWh-1用于解络和1.2 g kWh-1用于回收）。我们的研究结果突出了使用电动势具有成本效益的处理含有重金属的工业废水的潜力。
Heavy metals in industrial wastewaters are typically present as stable metal-organic complexes with their cost-effective treatment remaining a significant challenge. Herein, a self-enhanced decomplexation scenario is developed using an electrochemical membrane filtration (EMF) system for efficient decomplexation and Cu recovery. Using Cu-EDTA as a model pollutant, the EMF system achieved 81.5% decomplexation of the Cu-EDTA complex and 72.4% recovery of Cu at a cell voltage of 3 V. The •OH produced at the anode first attacked Cu-EDTA to produce intermediate Cu-organic complexes that reacted catalytically with the H2O2 generated from the reduction of dissolved oxygen at the cathode to initiate chainlike self-enhanced decomplexation in the EMF system. The decomplexed Cu products were further reduced or precipitated at the cathodic membrane surface thereby achieving efficient Cu recovery. By scavenging H2O2 (excluding self-enhanced decomplexation), the rate of decomplexation decreased from 8.8 × 10-1 to 4.1 × 10-1 h-1, confirming the important role of self-enhanced decomplexation in this system. The energy efficiency of this system is 93.5 g kWh-1 for Cu-EDTA decomplexation and 15.0 g kWh-1 for Cu recovery, which is much higher than that reported in the previous literature (i.e., 7.5 g kWh-1 for decomplexation and 1.2 g kWh-1 for recovery). Our results highlight the potential of using EMF for the cost-effective treatment of industrial wastewaters containing heavy metals.