Carbothermic Synthesis of Carbon-supported Zero-valent Iron Material for Removal of U(Ⅵ) from Aqueous Solution

doi:10.15541/jim20190378

Abstract

Abstract:

With the development of nuclear power, radioactive pollutants discharge into the environment and then contaminate soil and water resources. Nanoscale zero-valent iron (nZVI) materials are widely used in water remediation due to their strong reducibility and high removal efficiency. A carbon-based zero-valent iron material (Fe-CB) was prepared in this work. Fe-CB was fabricated using sodium alginate (SA) as a carbon source via one-step carbothermic method and then applied to eliminate U(Ⅵ) from aqueous solution. Its mechanism and adsorption properties of Fe-CB and U(VI) were studied by spectroscopic analyses and macroscopic experiments. The results illustrated that Fe-CB possessed of ample functional groups (such as -OH and -COOH) and high BET surface area, which made up for the dispersibility and low removal efficiency of nanoscale zero-valent iron (nZVI). The removal of U(VI) by Fe-CB achieved equilibrium in 3 h and the maximum sorption capacity was 77.3 mg·g ^-1 at 298 K. XPS analyses indicated that the U(Ⅵ) removal by Fe-CB was a synergistic effect of reductive adsorptive processes. Adsorption process resulted from surface complexation and the reduction process was dominated by U(VI) reduction to U(IV) by nZVI. The results show that Fe-CB can be used as an inexpensive and highly efficient pollutant scavenger, which has great potential for environment pollution management.

Key words: zero-valent iron, carbon material, uranium, adsorption, reduction

CLC Number:

X591

WANG Jiaqi, PANG Hongwei, TANG Hao, YU Shujun, ZHU Hongtao, WANG Xiangxue. Carbothermic Synthesis of Carbon-supported Zero-valent Iron Material for Removal of U(Ⅵ) from Aqueous Solution[J]. Journal of Inorganic Materials, 2020, 35(3): 373-380.

Figures/Tables 10

Fig. 1 SEM image (a), element mapping (b) and EDS pattern(c) of Fe-CB

Fig. 2 XRD patterns (a) and N2 adsorption-desorption isotherm (b) of SA, nZVI and Fe-CB; FT-IR spectra (c) of SA and Fe-CB; magnetization curve (d) of Fe-CB

Table 1 BET results of nZVI, SA and Fe-CB

Material	Specific surface area/(m²·g^-1)	Pore diameter/nm
nZVI	4.1	1.03
SA	0.2	2.12
Fe-CB	346.6	20.12

Fig. 3 Effect of contact time on the sorption of U(VI) by Fe-CB (a), and corresponding simulation of kinetics data by pseudo-first-order model (b) and pseudo-second-order model (c)

Table 2 Kinetic model parameters for remove of U(Ⅵ) by Fe-CB

Pseudo-first-order model			Pseudo-second-order model
k₁/min^-1	Q_e/(mg·g^-1)	R₁²	k₂/(g·mg^-1·min^-1)	Q_e/(mg·g^-1)	R₂²
0.4388	57.3	0.489	0.0026	64.3	0.998

Fig. 4 Adsorption isotherms (a) and linear plots of lnKd against Ce (b) for the elimination of U(Ⅵ) by Fe-CB at 328, 313 and 298 K

Table 3 Fitting parameters of adsorption isotherms for U(Ⅵ) on Fe-CB

T/K	Langmuir model			Freundlich model
T/K	Q_m/(mg·g^-1)	k_L/(L·mg^-1)	R₁²	k_F/(mg^1-ⁿ·Lⁿ·g^-1)	n	R₂²
298	77.3	1.40	0.971	62.6	18.62	0.788
313	89.7	1.54	0.970	71.1	16.29	0.884
328	103.7	1.25	0.959	76.4	12.15	0.901

Table 4 Thermodynamic parameters at different temperatures

T/K	ΔG^θ/(kJ·mol^-1)	ΔS^θ/(J·K^-1·mol^-1)	ΔH^θ/(kJ·mol^-1)
298	-5.74	34.84	4.64
313	-6.61
328	-7.72

Fig. 5 Effect of pH (a) and ionic strength (b) on U(Ⅵ) sorption by Fe-CB, Zeta-potential of Fe-CB (c), and relative distribution of U(VI) species in different pH (d)

Fig. 6 XPS survey spectra of Fe-CB before and after reaction with U(Ⅵ) (a), high resolution XPS spectrum of U4f (b), and deconvolution analyses of Fe2p (c); O1s (d) for Fe-CB before and after U(Ⅵ) adsorption

References 34

[1]	WU YI-HAN, PANG HONG-WEI, YAO WEN , et al. Synthesis of rod-like metal-organic framework (MOF-5) nanomaterial for efficient removal of U(VI): batch experiments and spectroscopy study. Sci. Bull., 2018,63(13):831-839.
[2]	WANG XIANG-XUE, YU SHU-JUN, WANG XIANG-KE . Removal of radionuclides by metal-organic framework-based materials. J. Inorg. Mater., 2019,34(1):17-26.
[3]	PANG HONG-WEI, DIAO ZHUO-FAN, WANG XIANG-XUE , et al. Adsorptive and reductive removal of U(VI) by dictyophora indusiate-derived biochar supported sulfide NZVI from wastewater. Chem. Eng. J., 2019,366:368-377.
[4]	WANG XIANG-XUE, CHEN LONG, WANG LIN , et al. Synthesis of novel nanomaterials and their application in efficient removal of radionuclides. Sci. China Chem., 2019,62(8):933-967.
[5]	CHEN ZHONG-SHAN, WANG JIAN, PU ZENG-XIN , et al. Synthesis of magnetic Fe₃O₄/CFA composites for the efficient removal of U(VI) from wastewater. Chem. Eng. J., 2017,320:448-457.
[6]	YU SHU-JUN, WANG XIANG-XUE, YANG SHI-TONG , et al. Interaction of radionuclides with natural and manmade materials using XAFS technique. Sci. China Chem., 2016,60(2):170-187.
[7]	LI XIAO-YAN, LIU YI-BAO, HUA MING , et al. Removal of U(VI) from aqueous solution by nanoscale zero-valent iron. Nucl. Power Eng., 2013,34(2):160-163.
[8]	PANG HONG-WEI, WU YI-HAN, HUANG SHU-YI , et al. Macroscopic and microscopic investigation of uranium elimination by Ca-Mg-Al-layered double hydroxide supported nanoscale zero valent iron. Inorg. Chem. Front., 2018,5(10):2657-2665.
[9]	LIU DA-QIAN, LIU ZHI-RONG, WANG CHANG-FU , et al. Removal of uranium(VI) from aqueous solution using nanoscale zero- valent iron supported on activated charcoal. J. Radioanal. Nucl. Chem., 2016,310(3):1131-1137.
[10]	ZHANG SI-HAI, WU MEI-FENG, TANG TING-TING , et al. Mechanism investigation of anoxic Cr(VI) removal by nano zero- valent iron based on XPS analysis in time scale. Chem. Eng. J.,, 2018,335:945-953.
[11]	TANG LIN, FENG HAO-PENG, TANG JING , et al. Treatment of arsenic in acid wastewater and river sediment by Fe@Fe₂O₃ nanobunches: the effect of environmental conditions and reaction mechanism. Water. Res., 2017,117:175-186.
[12]	CAO ZHEN, LIU XUE, XU JIANG , et al. Removal of antibiotic florfenicol by sulfide-modified nanoscale zero-valent iron. Environ. Sci. Technol., 2017,51(19):11269-11277.
[13]	XU CONG-BIN, YANG WEN-JIE, SUN HONG-LIANG , et al. Performance and mechanism of Pb(II) removal by expanded graphite loaded with zero-valent iron. J. Inorg. Mater., 2018,33(1):41-47.
[14]	YANG XIAO-DAN, WANG YU-RU, LI MIN-RUI . Preparation, modification of nanoscale zero valent iron and its application for the removal of heavy metals and organic pollutants from wastewater. Chem. Ind. Eng. Prog., 2019,38(7):3412-3424.
[15]	MAHDAVINA GHOLAM-REZA, RAHMANI ZEINAB, KARAMIN SHIVA , et al. Magnetic/pH-sensitive kappa-carrageenan/sodium alginate hydrogel nanocomposite beads: preparation, swelling behavior, and drug delivery. J. Biomater. Sci. Polym Ed., 2014,25(17):1891-1906.
[16]	LI DA-HAO, LÜ CHUN-XIAO, LIU LONG , et al. Egg-box structure in cobalt alginate: a new approach to multifunctional hierarchical mesoporous N-doped carbon nanofibers for efficient catalysis and energy storage. ACS Central Sci., 2015,1(5):261-269.
[17]	BERTAGNOLLI CAROLINE, CARLOS DA-SILVA, GUIBAL ERIC . Chromium biosorption using the residue of alginate extraction from sargassum filipendula. Chem. Eng. J., 2014,237:362-371.
[18]	PAPAGEORGIOU S K, KOUVELOS E P, KATSAROS F K . Calcium alginate beads from Laminaria digitata for the removal of Cu ²⁺ and Cd ²⁺ from dilute aqueous metal solutions . Desalination, 2008,224(1/2/3):293-306.
[19]	YI XIAO-FENG, SUN FU-LIANG, HAN FU-HAO , et al. Graphene oxide encapsulated polyvinyl alcohol/sodium alginate hydrogel microspheres for Cu(II) and U(VI) removal. Ecotox. Environ. Safe, 2018,158:309-318.
[20]	HU SHU-HONG, LIN XIAO-YAN, ZHAO WEN-HUI , et al. Efficient simultaneous removal of U(VI) and Cu(II) from aqueous solution using core-shell nZVI@SA/CMC-Ca beads. J. Radioanal. Nucl. Chem., 2018,315(2):223-235.
[21]	CHOE SANG-RAK, HALDORAI YUVARAJ, JANG SUNG- CHAN , et al. Fabrication of alginate/humic acid/Fe-aminoclay hydrogel composed of a grafted-network for the efficient removal of strontium ions from aqueous solution. Environ. Technol. Inno., 2018,9:285-293.
[22]	CHO EUNBEE, KIM JONGHO, PARK CHAN-WOO , et al. Chemically bound Prussian blue in sodium alginate hydrogel for enhanced removal of Cs ions. J. Hazard. Mater., 2018,360:243-249.
[23]	AGBOVI HENRY-K, WILSON LEE-D . Flocculation optimization of orthophosphate with FeCl₃ and alginate using the Box-behnken response surface methodology. Ind. Eng. Chem. Res., 2017,56(12):3145-3155.
[24]	LIU XIN, CHEN CHANG-FENG, YE HONG-WU , et al. One-step hydrothermal growth of carbon nanofibers and insitu assembly of Ag nanowire@carbon nanofiber@Ag nanoparticles ternary composites for efficient photocatalytic removal of organic pollutants. Carbon, 2018,131:213-222.
[25]	PANG HONG-WEI, HUANG SHU-YI, WU YI-HAN , et al. Efficient elimination of U(VI) by polyethyleneimine-decorated fly ash. Inorg. Chem. Front., 2018,5(10):2399-2407.
[26]	HU TAO, LIU QIN-ZE, GAO TING-TING , et al. Facile preparation of tannic acid-poly(vinyl alcohol)/sodium alginate hydrogel beads for methylene blue removal from simulated solution. ACS Omega, 2018,3(7):7523-7531.
[27]	MAHDAVINA GHOLAM-REZA, MOUSANEZHAD SEDIGHEH, HOSSEINZADEH HAMED , et al. Magnetic hydrogel beads based on PVA/sodium alginate/laponite RD and studying their BSA adsorption. Carbohydr. Polym., 2016,147:379-391.
[28]	WU YI-HAN, LI BI-YUN, WANG XIANG-XUE , et al. Magnetic metal-organic frameworks (Fe₃O₄@ZIF-8) composites for U(VI) and Eu(III) elimination: simultaneously achieve favorable stability and functionality. Chem. Eng. J., 2019,378:122105-122117.
[29]	LIU XIA, WANG XIANG-XUE, LI JIA-XING , et al. Ozonated graphene oxides as high efficient sorbents for Sr(II) and U(VI) removal from aqueous solutions. Sci. China Chem., 2016,59(7):869-877.
[30]	ZHU HONG-SHAN, YUAN JIN-YUN, TAN XIAO-LI , et al. Efficient removal of Pb ²⁺ by Tb-MOFs: identifying the adsorption mechanism through experimental and theoretical investigations. Environ. Sci.: Nano, 2019,6(1):261-272.
[31]	WU YI-HAN, LI BI-YUN, WANG XIANG-XUE , et al. Determination of practical application potential of highly stable UiO-66- AO in Eu(III) elimination investigated by macroscopic and spectroscopic techniques. Chem. Eng. J., 2019,365:249-258.
[32]	YU SHU-JUN, YIN LING, PANG HONG-WEI , et al. Constructing sphere-like cobalt-molybdenum-nickel ternary hydroxide and calcined ternary oxide nanocomposites for efficient removal of U(VI) from aqueous solutions. Chem. Eng. J., 2018,352:360-370.
[33]	XIA WEI, CHEN XING-XING, KUNDU SHANKHAMALA , et al. Chemical vapor synthesis of secondary carbon nanotubes catalyzed by iron nanoparticles electrodeposited on primary carbon nanotubes. Surf. Coat Tech., 2007,201(22/23):9232-9237.
[34]	SHENG GUO-DONG, YANG PENG-JIE, TANG YAN-NA , et al. New insights into the primary roles of diatomite in the enhanced sequestration of UO₂ ²⁺ by zerovalent iron nanoparticles: an advanced approach utilizing XPS and EXAFS. Appl. Catal. B-Environ., 2016,193:189-197.