Biochar
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2023
·Vol. 5
·期 1
·1-16
·
IF 12.7
Liu Fenglei,Wang Shanshan,Zhao Chaofeng,Hu Baowei
Herein, a biochar-based composite (Ti 3 C 2 T x @biochar-PDA/PEI) was constructed by decorating Ti 3 C 2 T x and polydopamine on coconut shell biochar via electrostatic self-assembly method. Different characterization techniques were applied to explore the structure, morphology and composition of the sorbents. It was found that the higher porosity and diverse functional groups were conducive for Ti 3 C 2 T x @biochar-PDA/PEI to capture radionuclides, and the water environmental conditions made a great contribution to the adsorption process. The process of removing U(VI)/Cs(I) well complied with the Langmuir isotherm and Pseudo-second-order equations, which indicated that the single layer chemical adsorption occurred on the solid liquid interface. Meanwhile, this produced composite exhibited superior removal performance under complex co-existing ion environment, and the maximum adsorption amounts of U(VI) and Cs(I) reached up to 239.7 and 40.3 mg g −1 . Impressively, this adsorbent still exhibited good adsorption performance after three cycles of regeneration. The spectral analysis and DFT calculation demonstrated that adsorption of U(VI) might be a chemical process, while the adsorption of Cs(I) should be ion exchange or electrostatic attraction. This study demonstrated the potential application of Ti 3 C 2 T x @biochar-PDA/PEI as an effective remediation strategy for radioactive wastewater cleanup. Graphical Abstract
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
NUCLEAR TECHNOLOGY
·
2022
·
IF 1.667
Yanhui Wang,Qiao Jiang,Yexin Yang,Jianfeng Cheng,Chenyang Bao,Yuelong Pan,Yu Liu,Gang Yang,Yangchun Leng,Xianguo Tuo
The alteration of the morphology of bentonite, a key barrier to isolating high-level radioactive waste in deep geological repositories under long-term interaction with groundwater, was studied. Bentonite colloids were prepared from Gaomiaozi bentonite, and its various properties were analyzed by various characterization methods. The effects of various factors on the adsorption of Cs(I) and Co(II) on bentonite colloids were investigated by batch static adsorption experiments. The results showed that the colloids were mainly composed of montmorillonite and were lamellar in shape, with a zeta potential of −enton mV and an average size of approximately 209.10 nm. The adsorption of Cs(I) and Co(II) by the colloids was a rapid process, and 31.78 and 88.24 mg/g, respectively, were adsorbed at equilibrium. Pseudo-second-order kinetic fitting showed that chemisorption plays a dominant role and acid-base interactions affect adsorption by influencing the stability of colloids and the chemical form of simulated nuclides. This work can be helpful for evaluating the safety of waste repositories.
研究领域:
环境科学
·
放射性废物管理
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2017
·
IF 3.359
Fuyin Ma,Zheng Li,Haogui Zhao,Yiyun Geng,Wei Zhou,Qingnuan Li,Lan Zhang
As a new carbon-based membrane material used for ionic and molecular sieving, the graphene oxide (GO) membrane also has potential application in radiochemical separation. In this work, the permeation performances of some typical metallic elements in high level-liquid waste (HLLW) through the ionic sieving 5-μm-thick GO membranes were investigated. It was found that the permeation rates of ions through GO membranes markedly decreased with the increase of hydrated ionic radii. Cs(I) and Sr(II) permeated through GO membranes quickly, whereas lanthanide ions and actinide ions infiltrated much more slowly, thus providing the feasibility of separation according to the difference of hydrated ionic radii. Moreover, the concentrations of initial metal ions and acidity in feed solutions also had influences on the permeation of ions through GO membranes, and higher initial metal ions and feed solution acidity were favorable to the removal of Cs(I) and Sr(II). The barrier separation test indicated that GO membranes had promising ability for the separation of Cs(I) and Sr(II) from lanthanide and actinide ions due to the difference of hydrated ion radius, and the separation factor of Cs(I)/U(VI) and Sr(II)/U(VI) would reach about 10 and 3 in single penetration. The presented results demonstrated that the membrane separation based on GO membrane would be a promising candidate for the removal of Cs(I) and Sr(II) from HLLW.
研究领域:
放射化学
·
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2019
·
IF 5.107
Sharafat Ali,Izaz Ali Shah,Haiou Huang
The need for high-performance and novel technologies for selective treatment of radionuclides in water has recently stimulated broad research. In this study, we examined the ability of carbon nanotube (CNT) membranes in selective removal of strontium (Sr 2+ ) and cesium (Cs + ) from water and wastewater. In single-metal systems that contained only Sr 2+ , Cs + or their competitive metal ions, the distribution coefficients ( K d ) of functionalized CNT membranes for divalent cations, i.e., Sr 2+ , Ca 2+ , and Mg 2+ , were measured as 4.41 mmol g −1 , 2.14 mmol g −1 , and 1.30 mmol g −1 , respectively, and those for monovalent cations, i.e., Cs + , K + and Na + , were 0.81 mmol g −1 , 0.79 mmol g −1 , and 0.81 mmol g −1 , respectively. When Cs + or Sr 2+ co-existed with a competing cation, both pristine and functionalized CNT membranes showed excellent selectivity to Sr 2+ over Mg 2+ and Ca 2+ while their selectivity to Cs + over K + and Na + diminished. Moreover, the CNT membranes remained their selectivity for Sr 2+ in a wastewater effluent despite the complex water composition. Overall, the selectivity sequence of the CNT membranes for divalent cations support the occurrence of inner-sphere complexation on CNT surfaces, while that for the monovalent cations was probably determined by electrostatic interactions. This study demonstrates that Ar/O 2 plasma treatment is a greener technology for the production of CNT functionalized membranes for selective removal of contaminants from water to achieve “fit-for-purpose” treatment.
研究领域:
环境科学
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材料科学
·
水处理技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF DISPERSION SCIENCE AND TECHNOLOGY
·
2020
·
IF 1.701
Long Wang,Zhiming Wang,Cuo Zhou,Weijun Song,Chunyan Sun
A cesium potentiometric microsensor based on magnetic ion-imprinted polymer (MIIP) has been developed for Cs(I) sensing. The core-shell structure Cs(I)-MIIP was synthesized by surface-imprinting technique, using functionalized magnetic Fe3O4@SiO2 microspheres, Cs(I) ion and carboxymethyl chitosan as supporter, template and functional monomers respectively. The resultant Cs(I)-MIIP was used as ionophore in the construction of the PVC membrane electrode to obtain a selective potentiometric microsensor toward Cs(I) ions. The fabricated sensor exhibited a highly sensitive Nernstian response (60.2 mV/decade) over the concentration range of 1 × 10−6 to 1 × 10−1 M of Cs(I). The response time of the microsensor was considerably short (less than 3 s) and its detection limit was determined as 3.0 × 10−7 M. The microsensor was effectively performed in the pH range of 4–6, and revealed desirable selectivity over a wide variety of other cations including alkali, alkaline earth and heavy metals. The proposed microsensor was also used for the determination of Cs(I) contents in the environmental water samples. The potentiometric results were in good harmony with the results obtained by the ICP-MS method.
研究领域:
分析化学
·
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
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