Reductive immobilization and long-term remobilization of radioactive pertechnetate using bio-macromolecules stabilized zero valent iron nanoparticles  

作　　者：Haodong Ji Yangmo Zhu Jun Duan Wen Liu Dongye Zhao 

机构地区：[1]The Key Laboratory of Water and Sediment Science,Ministry of Education,College of Environment Science and Engineering,Peking University,Beijing 100871,China [2]Environmental Engineering Program,Department of Civil Engineering,Auburn University,Auburn,AL 36849,United States [3]The Beijing Innovation Center for Engineering Science and Advanced Technology(BIC-ESAT),Peking University,Beijing 100871,China [4]Institute of Environmental Science,Taiyuan University of Science and Technology,Taiyuan 030024,China

出　　处：《Chinese Chemical Letters》2019年第12期2163-2168,共6页中国化学快报（英文版）

基　　金：partially supported by the National Natural Science Foundation of China(No.41230638);a grant from the USDA AAES 2015 Hatch and Multistate funding program

摘　　要：Reductive immobilization of radioactive pertechnetate(99TcO4^-) in simulated groundwater was studied by prepared carboxymethyl cellulose(CMC) and starch stabilized zero valent iron nanoparticles(nZVI),and long-term remobilization of reduced Tc was also evaluated under anoxic and oxic conditions.The stabilized nZVI can effectively reduce soluble 99Tc(Ⅶ) to insoluble 99 Tc(Ⅳ),and they can be easily delivered into a contaminated groundwater zone and facilitate in situ remediation.In this study,CMCstabilized nZVI showed higher reactivity than that using starch as the stabilizer.Batch experiments indicated that more than 99% of 99 Tc(Ⅶ)(CO=12 mg/mL) was reduced and removed from groundwater by CMC-stabilized nZVI with a CMC content of 0.2%(w/w) at a broad pH of 5-8.X-ray diffraction(XRD)and X-ray photoelectron spectroscopy(XPS) analyses further confirmed that 99Tc(Ⅶ)O4^-transformed into 99Tc(Ⅳ)O2(s).The presence of bicarbonate exhibited insignificant effect on Tc immobilization,while humic acid(HA) inhibited reaction mainly due to retardation on electron transfer and formation of Tc(IV)-HA complexes.More interesting,the immobilized Tc(Ⅳ) remained insoluble even after 120 d under anoxic condition,while only^21 % was remobilized when exposed to air.Therefore,biomacromolecules stabilized nZVI nanoparticles could be a viable alternative for in situ remediation of radioactive contamination in groundwater.Reductive immobilization of radioactive pertechnetate(99TcO4-) in simulated groundwater was studied by prepared carboxymethyl cellulose（CMC） and starch stabilized zero valent iron nanoparticles（nZVI）,and long-term remobilization of reduced Tc was also evaluated under anoxic and oxic conditions.The stabilized nZVI can effectively reduce soluble 99Tc（Ⅶ） to insoluble 99 Tc（Ⅳ）,and they can be easily delivered into a contaminated groundwater zone and facilitate in situ remediation.In this study,CMCstabilized nZVI showed higher reactivity than that using starch as the stabilizer.Batch experiments indicated that more than 99% of 99 Tc（Ⅶ）（CO=12 mg/mL） was reduced and removed from groundwater by CMC-stabilized nZVI with a CMC content of 0.2%（w/w） at a broad pH of 5-8.X-ray diffraction（XRD）and X-ray photoelectron spectroscopy（XPS） analyses further confirmed that 99Tc（Ⅶ）O4-transformed into 99Tc（Ⅳ）O2（s）.The presence of bicarbonate exhibited insignificant effect on Tc immobilization,while humic acid（HA） inhibited reaction mainly due to retardation on electron transfer and formation of Tc（IV）-HA complexes.More interesting,the immobilized Tc（Ⅳ） remained insoluble even after 120 d under anoxic condition,while only～21 % was remobilized when exposed to air.Therefore,biomacromolecules stabilized nZVI nanoparticles could be a viable alternative for in situ remediation of radioactive contamination in groundwater.

关 键 词：Reductive immobilization Radionuclide Stabilized nanoparticles Zero valent iron Groundwater Technetium 

分 类 号：TB383.1[一般工业技术—材料科学与工程]