Chen Ying, Mu Yi, Tian Lei, Zheng Ling-Ling, Mei Yi, Xing Qiu-Ju, Liu Wen, Zou Jian-Ping, Yang Lixia, Luo Shenglian, Wu Daishe
Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle, Nanchang Hangkong University, Nanchang 330063, P. R. China.
Key Laboratory of Poyang Lake Environment and Resource Utilization, Ministry of Education, School of Resources & Environment, Nanchang University, Nanchang 330031, P. R. China.
Environ Sci Technol. 2023 Mar 28;57(12):5034-5045. doi: 10.1021/acs.est.3c00190. Epub 2023 Mar 14.
Traditional methods cannot efficiently recover Cu from Cu(II)-EDTA wastewater and encounter the formation of secondary contaminants. In this study, an ozone/percarbonate (O/SPC) process was proposed to efficiently decomplex Cu(II)-EDTA and simultaneously recover Cu. The results demonstrate that the O/SPC process achieves 100% recovery of Cu with the corresponding value of 0.103 min compared with the typical OH-based O/HO process (81.2%, 0.042 min). The carbonate radical anion (CO) is generated from the O/SPC process and carries out the targeted attack of amino groups of Cu(II)-EDTA for decarboxylation and deamination processes, resulting in successive cleavage of Cu-O and Cu-N bonds. In comparison, the OH-based O/HO process is predominantly responsible for the breakage of Cu-O bonds via decarboxylation and formic acid removal. Moreover, the released Cu(II) can be transformed into stable copper precipitates by employing an endogenous precipitant (CO), accompanied by toxic-free byproducts in the O/SPC process. More importantly, the O/SPC process exhibits excellent metal recovery in the treatment of real copper electroplating wastewater and other metal-EDTA complexes. This study provides a promising technology and opens a new avenue for the efficient decomplexation of metal-organic complexes with simultaneous recovery of valuable metal resources.
传统方法无法有效地从Cu(II)-EDTA废水中回收铜，并且会产生二次污染物。在本研究中，提出了一种臭氧/过碳酸盐（O/SPC）工艺，以有效地分解Cu(II)-EDTA并同时回收铜。结果表明，与典型的基于羟基自由基的O/HO工艺（81.2%，0.042分钟）相比，O/SPC工艺实现了100%的铜回收率，相应的 值为0.103分钟。O/SPC工艺产生碳酸根自由基阴离子（CO），并对Cu(II)-EDTA的氨基进行靶向攻击，以进行脱羧和脱氨过程，从而导致Cu-O和Cu-N键的连续断裂。相比之下，基于羟基自由基的O/HO工艺主要通过脱羧和去除甲酸来导致Cu-O键的断裂。此外，通过使用内源性沉淀剂（CO），释放出的Cu(II)可以转化为稳定的铜沉淀物，并且在O/SPC工艺中产生无毒的副产物。更重要的是，O/SPC工艺在处理实际电镀铜废水和其他金属-EDTA络合物时表现出优异的金属回收率。本研究提供了一种有前景的技术，并为金属有机络合物的高效分解以及同时回收有价值的金属资源开辟了一条新途径。
