%0 Journal Article
%J Separation and Purification Technology
%D 2023
%T Extremely efficient mineralizing CN− into N2 via a newly developed system of generating sufficient ClO•/Cl2•− and self-decreasing pH
%A Lei Tian
%A Meng-Ying Yin
%A Ling-Ling Zheng
%A Ying Chen
%A Liu, Wen
%A Jie-Ping Fan
%A Dai-She Wu
%A Jian-Ping Zou
%A Sheng-Lian Luo
%K Advanced oxidation processes
%K Cyanide
%K Electrocatalysis
%K Mineralization
%K nitrogen
%X In the presence of the difficulties pertinent to the selective oxidation of cyanide and the high-efficient hydrolysis of cyanate, the mineralization of cyanide into nitrogen could not be realized during the traditional processes. Herein, a novel system of electrocatalysis coupled with ultraviolet-based advanced oxidation processes (UV/EC/PS, PS: persulfate) is developed, exhibiting astonishingly high activity and selectivity for cyanide mineralization. The achieved results reveal that adequate active-chlorine species (ClO•/Cl2•−) are generated due to the synergistic effects of electrocatalysis and advanced oxidation processes and these are high-selective for cyanide mineralization. Concurrently, induced by the interconversion between active species, the pH value in the UV/EC/PS system vigorously lessens from 11.5 to 3.3 at a rate of 1.1 × 10-2 min−1, hugely speeding up the hydrolysis of cyanate intermediates. The results display that PS plays a pivotal role in the formation of ClO•/Cl2•− and the self-reduction of pH value in the UV/EC/PS system. Under the action of ClO•/Cl2•− and self-decreased pH value, 0.25 mM of ferricyanide is thoroughly mineralized into nitrogen within 80 min and no HCN evolves. Additionally, the UV/EC/PS system exhibits exceptional feasibility for the practical purifications of cyanide-containing wastewater (CCWW). This study aims to give new insights into developing technologies associated with the mineralization treatment of CCWW.
%B Separation and Purification Technology
%V 309
%P 123021
%G eng
%U http://www.sciencedirect.com/science/article/pii/S1383586622025783
%R http://doi.org/10.1016/j.seppur.2022.123021