High-efficiency degradation of Fe-CNs in SPL through microwave-activated persulfate
Document Type
Article
Publication Date
2-1-2024
Department
Department of Materials Science and Engineering
Abstract
Cyanide in spent potlining (SPL) is primarily present as sodium cyanide (NaCN) and iron (II, III) cyanide complexes (Fe-CNs). NaCN is easy to degrade, while Fe-CNs is extremely difficult to degrade. In this work, a novel microwave-activated persulfate technology (MW-PS) was firstly proposed to degrade Fe-CNs promptly and efficiently. The removal rate of 99.88 % was achieved within 180 s under optimal conditions of pH = 10.15, [oxidant]:[Fe-CNs] molar ratio of 5:1, and microwave power of 300 W. The remaining total cyanide content was less than 0.04 mg·L−1. The degradation mechanism of ferrocyanide (II) and ferricyanide (III) in the MW-PS degradation system was systematically analyzed through electron paramagnetic resonance (EPR) and element identification techniques. The ROS (SO4[rad]−, HO[rad], O2[rad]−, and 1O2) generated under microwave activation and first attacked the C-Fe complex bond in Fe-CNs, causing the bond to dissociate and release the free CN−, and then CN− was thoroughly oxidized. This work develops a simple and high-efficiency decyanation technology for complex cyanide contained industrial waste disposal.
Publication Title
Separation and Purification Technology
Recommended Citation
Li, Z.,
Su, X.,
Feng, J.,
Huang, A.,
Mo, W.,
Ma, S.,
Hwang, J.,
Jia, H.,
&
Lin, H.
(2024).
High-efficiency degradation of Fe-CNs in SPL through microwave-activated persulfate.
Separation and Purification Technology,
330 Part B.
http://doi.org/10.1016/j.seppur.2023.125575
Retrieved from: https://digitalcommons.mtu.edu/michigantech-p2/278