Fe单原子催化剂活化过一硫酸盐去除水中有机物

Activated peroxymonosulfate by Fe single-atom catalyst for removing organic pollutants in water

采用聚吡咯水凝胶法制备了高Fe负载量(w)的Fe-N/P-C单原子催化剂,运用HAADF-STEM对其进行了表征,研究了其活化过一硫酸盐(PMS)降解双酚A(BPA)和二级出水中溶解性有机物(DOM)的性能。实验结果表明:对于BPA溶液,Fe负载量为2.32%、4.72%和6.74%时,BPA降解的反应速率常数分别为0.65,0.92,0.83 min^(-1),反应60 min后,TOC去除率分别为73%、80%和78%,BPA去除率分别为98%、100%和100%;对于加入BPA的二级出水,Fe负载量为2.32%和4.72%时,BPA降解的反应速率常数分别为0.43 min^(-1)和0.76 min^(-1),反应60 min后,TOC去除率分别为49%和56%,BPA去除率分别为80%和100%,DOM荧光强度分别增强32%和降低46%;Fe-N/P-C活化PMS体系中,超氧自由基和单线态氧为主要活性氧物种,Fe为活化PMS的活性中心。

Fe-N/P-C single-atom catalysts(SACs)with high Fe loading(w)were prepared by the polypyrrole hydrogel method and characterized by HAADF-STEM.The performance of activated peroxymonosulfate(PMS)to degrade bisphenol A(BPA)and dissolved organic matter(DOM)in secondary effluent was investigated.The experimental results show that when the Fe loading is 2.32%,4.72%,and 6.74%,the reaction rate constant of BPA degradation is 0.65,0.92 and 0.83 min^(-1),the total organic carbon(TOC)removal rate is 73%,80%,and 78%and the BPA removal rate is 98%,100%,and 100%after 60 min of reaction,respectively.For the secondary effluent with BPA,when the Fe loading is 2.32%and 4.72%,the reaction rate constant of BPA degradation is 0.43 min^(-1)and 0.76 min^(-1),the TOC removal rate is 49%and 56%,the BPA removal rate is 80%and 100%,and the DOM fluorescence intensity increases by 32%and decreases by 46%after 60 min of reaction,respectively.In the Fe-N/P-C/PMS reaction system,superoxide radicals and singlet oxygen are the main reactive oxygen species,and the Fe atom is the active center for activating PMS.