An efficient approach for the treatment of radioactive waste perfluoropolyether lubricants via a synergistic effect of thermal catalysis and immobilization  

作　　者：Xinhang Du Wenhua Tong Xinyu Zhou Jia Luo Yuqiu Liu Yabo Wang Panyu Li Yongkui Zhang 

机构地区：[1]Department of Pharmaceutical&Biological Engineering,School of Chemical Engineering,Sichuan University,Chengdu 610065,China

出　　处：《Journal of Environmental Sciences》2024年第2期512-522,共11页环境科学学报（英文版）

基　　金：Sichuan Science and Technology Program (No.2021YJ0482);the Fundamental Research Funds for the Central Universities (No.2021SCU12087)。

摘　　要：Perfluoropolyether(PFPE)lubricants are a kind of high-molecular polymer with many excellent properties.However,the use of PFPEs in the nuclear industry can lead to partial decomposition and carrying radionuclides,resulting in a large amount of radioactive waste PFPE lubricants annually.Moreover,radioactive waste PFPE lubricants are difficult to be effectively treated due to their high stability,the risk of possible leakage of radionuclides,and hypertoxic fluorine-containing by-products.In this study,without any precedent,a strategy of Mn O_(2)-catalyzed decomposition and Na_(2)CO_(3)-immobilized conversion was proposed for PFPE lubricant decomposition and fluorine immobilization simultaneously based on the Lewis acid-base and oxygen vacancies concept.A high fluorine conversion efficiency of 95.4%was achieved.Meanwhile,the mechanism of decomposition suggested that Mn O_(2)mainly provided Lewis acid sites and attacked the(basic)fluorine or oxygen atoms in PFPE molecules.The decomposition of PFPE chains was proceed down and volatile fluorine-containing gas was released by partial electron transfer,intramolecular disproportionation reaction,and unzipping fashion.Subsequently,gas by-products could be further oxidized and then immobilized into fluoride salts by carbonate solid absorbents.Overall,this study provides a simple,safe,and potentially practical strategy for the harmless conversion of refractory fluorinated organic wastes,especially perfluoropolymers.

关 键 词：Perfluoropolyether lubricants Catalyzed decomposition Fluorine-containing gas Immobilized conversion FLUORIDE 

分 类 号：X591[环境科学与工程—环境工程]