Dication-accelerated anion transport inside micropores for the rapid decontamination of pertechnetate

作     者：Peng Zhang Yi-Zhi Chen Han-Qin Weng Zi-Fang Guo Jia-Liang Chen Xing Zhao Guo-An Ye Ming-Zhang Lin Peng Zhang;Yi-Zhi Chen;Han-Qin Weng;Zi-Fang Guo;Jia-Liang Chen;Xing Zhao;Guo-An Ye;Ming-Zhang Lin

作者机构：School of Nuclear Science and TechnologyUniversity of Science and Technology of ChinaHefei 230026China Department of Beam Material ScienceSANKENThe Institute of Scientific and Industrial ResearchOsaka University8-1 MihogaokaIbarakiOsaka 567-0047Japan Radiochemistry Department of China Institute of Atomic EnergyChina Institute of Atomic EnergyBeijing 102413China 

出 版 物：《Nuclear Science and Techniques》 (核技术（英文）)

年 卷 期：2022年第33卷第4期

页      面：19-32页

核心收录：

学科分类：083002[工学-环境工程] 0830[工学-环境科学与工程（可授工学、理学、农学学位）] 08[工学] 

基　　金：supported by the National Natural Science Foundation of China(Nos.51803205,11775214,and 21790371) China Scholarship Council(No.201906345006). 

主　　题：Quaternary pyridinium Dicationic pyridyl derivatives Pertechnetate Intraparticle diffusion 

摘      要：Over 70%of the treated contaminated water at the Fukushima Daiichi Nuclear Power Station contains radionuclides beyond the regulatory standard for discharge that need to be re-purified.Technetium-99(^(99)Tc),mainly in the form of pertechnetate Tc(VII)O_(4)^(-),is one of the main sources of long-term radiotoxicity that jeopardizes the environment and human health.Herein,we used a series of dicationic pyridinium(DCP)derivative groups(–Py^(+)C_(n)H_(2n)N^(+)Me_(3),n=2,3,and 5)to modify commercial Reillex 425 resins containing tertiary pyridyl groups to improve the adsorption performance of rhenium(Re,an analog of radioactive Tc)and Tc.As the quaternary pyridinium and ammonium sites in one DCP group can adsorb ReO_(4)^(-) simultaneously,DCP-modified Reillex 425(Reillex-Cn)exhibited high maximum adsorption capacities for Re under neutral conditions.Adsorption capacities reached 344.8,416.7,and 588.2 mg g^(-)1 for Reillex 425-C2,Reillex 425-C3,and Reillex 425-C5,respectively.Intraparticle diffusion of ReO_(4)^(-)/TcO_(4)^(-) in Reillex 425-Cn was verified to be the rate-limiting step of adsorption.However,adsorption can be adjusted by the length of the alkyl spacers between the two positively charged N sites in DCP.–Py^(+)C_(2)H_(4)N^(+)Me_(3) significantly enhanced intraparticle diffusion compared to–Py^(+)C_(5)H_(10)N^(+)Me_(3).The two positive sites in–Py^(+)C_(2)H_(4)N^(+)Me_(3) would be laterally distributed,leading to a smaller steric hindrance for ReO_(4)–/TcO_(4)^(-) transport inside the microporous channels.Meanwhile,the longer alkyl spacers in–Py^(+)C_(5)H_(10)N^(+)Me_(3) formed hydrophobic microphases,repulsing the hydrated ReO_(4)–/TcO_(4)^(-) anions.Thus,the adsorptions of both ReO_(4)^(-) and TcO_(4)^(-) on Reillex 425-C2 were faster than those on Reillex 425-C5.Moreover,Reillex 425-Cn exhibited an exothermic nature,good selectivity,excellent reusability,and strong salinity tolerance.This study provides a simple strategy to enhance the Tc removal performance of adsorbents containing abundant micropores,which implies enormous environmental and economic benefits.