Precise separation and efficient recovery of Pd(Ⅱ)from high-level liquid waste by XAD-based adsorbents  

作　　者：Hao-Ran Dong Shun-Yan Ning Zeng-Yuan Li Si-Zhi Xu Feng-Tao Hu Feng Gao You-Bin Wang Li-Feng Chen Xiang-Biao Yin Toyohisa Fujita Mohammed FHamza Yue-Zhou Wei 

机构地区：[1]School of Resources,Environment and Materials,Guangxi University,Nanning 530004,China [2]School of Nuclear Science and Technology,University of South China,Hengyang 421001,China

出　　处：《Rare Metals》2024年第10期5372-5390,共19页稀有金属（英文版）

基　　金：financially supported by the National Natural Science Foundation of China(Nos.22066005,U1967218 and 11975082);the Science and Technology Innovation Program of Hunan Province(No.2023RC1067);the Natural Science Foundation of Guangxi Province(No.2021GXNAFAA220096)。

摘　　要：Efficient separation of palladium(Pd(Ⅱ))from high-level liquid waste(HLLW)not only helps the safe disposal of nuclear waste,but also is a vital importan supplement to Pd(Ⅱ)resources.Herein,16 kinds of nove Amberlite XAD resins-based adsorbents were prepared by vacuum impregnation method for the separation of Pd(Ⅱ)from simulated HLLW,and the MMBT/XAD7HP prepared using 4-methyl-2-mercaptobenzothiazole(MMBT)as ligand and Amberlite XAD7HP resin(XAD7HP)as the carrier was selected as the optimal research object.Characterization analysis experiments proved the successful preparation of MMBT/XAD7HP,which exhibited ultrahigh adsorption selectivity for Pd(Ⅱ)(distribution coefficient(K_d)≥12584.5 ml·g^(-1),separation factor(SF_(Pd/M))≥2818.4)and superior adsorption capacity(Q≥130.1 mg·g^(-1)).The adsorption kinetics and adsorption isotherms for Pd(Ⅱ)matched with pseudo-secondorder(PSO)kinetics model and Langmuir model,indicating that the adsorption mode for Pd(Ⅱ)by MMBT/XAD7 HP was monolayer chemical adsorption.The dynamic column experiments showed that MMBT/XAD7 HP achieved efficiently separation of Pd(Ⅱ)from simulated HLLW,and the recovery rate was nearly 100% The adsorption mechanism was analyzed by Fourier transform infrared spectroscopy(FTIR),X-ray photoelectron spectroscopy(XPS)and density functional theory(DFT),and the ultrahigh selectivity of MMBT/XAD7 HP is attributed to the preferred affinity of the soft-N,S donor atoms in MMBT for Pd(Ⅱ).MMBT has the shortest frontline molecular orbital energy band gap(HOMO-LUMO)among the four ligands,which makes it easier to become an electron donor to attract Pd^(2+)to participate in coordination.NO_(3)^(-)participates in the adsorption to keep charge balance.In summary,MMBT/XAD7 HP has broad application prospects for the treatment of Pd(Ⅱ)in HLLW.

关 键 词：XAD PALLADIUM HLLW ADSORPTION Column experiments 

分 类 号：TQ424[化学工程] X703[环境科学与工程—环境工程]