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 

机构地区：[1]School of Nuclear Science and Technology,University of Science and Technology of China,Hefei 230026,China [2]Department of Beam Material Science,SANKEN,The Institute of Scientific and Industrial Research,Osaka University,8-1 Mihogaoka,Ibaraki,Osaka 567-0047,Japan [3]Radiochemistry Department of China Institute of Atomic Energy,China Institute of Atomic Energy,Beijing 102413,China

出　　处：《Nuclear Science and Techniques》2022年第4期19-32,共14页核技术（英文）

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

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

关 键 词：Quaternary pyridinium Dicationic pyridyl derivatives PERTECHNETATE Intraparticle diffusion 

分 类 号：X771[环境科学与工程—环境工程]