REACTIVE & FUNCTIONAL POLYMERS
·
2019
·
IF 3.074
Lihua Liu,Zhengchi Yang,Lu Zhao,Gang Su,Zuoxiao Wei,Anping Tang,Jianrong Xue
A novel poly(N 1 ,N 1 ,N 6 ,N 6 -tetraallylhexane-1,6-diammonium dichloride) (PTAHDADC) microparticle was prepared via inverse emulsion polymerization . The adsorption characteristics and mechanism for Mo(VI) in an aqueous solution were investigated systemically. Results showed that PTAHDADC had a high positively charge density with a positive charge at every six CH 2 (or CH ) units and presented a coral-like morphology, with macropores distributed in 30–130 μm, and a porosity of up to 46.52%. The Mo(VI) removal efficiency was >99% at pH = 3.0–4.0. The adsorption data could be effectively described using the Langmuir and pseudo-second-order kinetic models . The maximum adsorption capacity was up to 394.11 mg·g −1 at 293 K. The adsorption process was rapid, and reached equilibrium within 120 min with an adsorption activation energy E a of 41.15 kJ·mol −1 . The adsorption process of Mo(VI) by PTAHDADC was accompanied by the partial ion exchange of counterion Cl − , the partial deprotonation of functional groups ( CH 2 ) 3 N + H on PTAHDADC, and the new interaction and bond formation between Mo(VI) and PTAHDADC. Mo(VI) removal by PTAHDADC was a process of spontaneously endothermic entropy increment, which involves physisorption , electrostatic attraction, ion exchange, and chemisorption . PTAHDADC offers a simple synthesis and excellent adsorption performance and recyclability. Therefore, PTAHDADC is a highly potential adsorbent for removing Mo(VI) ions from wastewater and has a broad application prospect.
研究领域:
环境科学
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材料科学
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DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2024
·
IF 7.4
Guihong Han,Lulu Kou,Zhan Chu,Wenjuan Wang,Hongfei Ma,Bingbing Liu,Hu Sun,Shuzhen Yang,Yanfang Huang
Treatment of molybdenum-containing wastewater is crucial for mitigating the environmental threat of Mo(VI) ions and recovering valuable metals. Compared to conventional separation methods, adsorbing colloid flotation emerges as a viable way to efficiently remove Mo(VI) ions. However, the current colloidal adsorption reagents have constrained the development of adsorbing colloid flotation due to their poor removal efficiency and narrow solution pH range. To overcome these challenges, Zr(IV) salts and La(III) salts were employed as colloidal adsorption reagents for the first time to remove Mo(VI) ions from wastewater in this work. In particular, the differences in removal efficiency of Mo(VI) ions between Zr(IV) salts, La(III) salts and traditional Fe(III) salts were systematically evaluated over a wide solution pH range. Zr(IV) salts demonstrated robust pH stability, displaying a significant removal efficiency of over 70.00% for Mo(VI) ions during the colloidal adsorption stage across a broad solution pH range from 3 to 11. Even more astonishingly, the removal efficiency of Mo(VI) ions was further enhanced through the synergistic effect of cetyltrimethylammonium bromide (CTAB) during the flotation separation stage. Under the optimal conditions of bubble flotation, the solution turbidity decreased rapidly from 164.50 NTU to 3.33 NTU, and the removal efficiency of Mo(VI) ions reached an impressive 99.10% which was enhanced by 23.73% compared to the colloidal adsorption stage. In conclusion, Zr(IV) salts, serving as colloidal adsorption reagents, have overcome the limitations of traditional colloidal adsorption reagents and exhibit significant potential for the removal of Mo(VI) ions from wastewater.
研究领域:
环境科学
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化学工程
·
废水处理
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DOI
高影响因子
APPLIED CLAY SCIENCE
·
2021
·
IF 5.467
Lei Wang,Haris Muhammad,Minwang Laipan,Xiaohu Fan,Junkang Guo,Yongtao Li
The demand for clean water and soil drives high efficiency, less expensive, and eco-friendly clay-composites as adsorbents for remediation of heavy metals polluted environment. We have developed a new water remediation technique by using an organic-inorganic composite, L-cysteine doped polypyrrole modified bentonite (L-cys/PPy/BT) for removal of Cr(VI) and Mo(VI). The L-cys/PPy/BT showed maximum adsorption capacities of 318.5 and 65.4 mg/g for Cr(VI) and Mo(VI) respectively. For Cr(VI) and Mo(VI) the sorption process on L-cys/PPy/BT followed the Freundlich and Langmuir isotherm models, respectively. Furthermore, the pseudo-second-order kinetic model described the adsorption behavior of Cr(VI) and Mo(VI). Moreover, the thermodynamic parameters indicated that sorption processes were endothermic and spontaneous. Mechanistic assessment revealed that adsorption of Mo(VI) on L-cys/PPy/BT could be attributed to chelation, electrostatic attraction and ion-exchange of Mo(VI) with the imine/amine functional groups in the material's matrix , while electrostatic attraction, ion exchange, chelation and redox reaction played a significant role in the removal of Cr(VI). This research provides a new approach for the use of clay materials as potential sorbents for removal of heavy metal ions in contaminated water .
研究领域:
环境科学
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材料科学
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DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Feiyu Gao,Chaowen Tan,Yang You,Yong Hou,Hongyan Yan,Xuewei Lv,Jie Dang
The imperative need for efficient and selective adsorption of Ni(II) and Mo(VI) is crucial for resource utilization and environmental protection. However, this process faces a challenge due to the scarcity of adsorbents that can adeptly adsorb both metal ions simultaneously. To address this, this study introduces a novel composite adsorbent material, denoted as BECZN, achieved through composite cross-linking of waste orange peel biochar with in situ aminated cobalt/zinc-zeolitic imidazolate frameworks (Co/Zn-ZIF-NH 2 ). The incorporation of Co/Zn-ZIF-NH 2 enhances the availability of active groups within BECZN. The aerogel structure of BECZN prevents ZIF material collapse and agglomeration, thereby improving active site exposure. BECZN exhibits notable adsorption capacities, reaching 151.84 mg/g for Ni(II) at pH = 7 and 842.54 mg/g for Mo(VI) at pH = 3. Further investigations indicated that the adsorption of Ni(II) and Mo(VI) obeys the Langmuir isotherm model, while exhibiting pseudo-second-order kinetics and intraparticle diffusion characteristics. Notably, BECZN selectively adsorbs Ni(II) and Mo(VI) efficiently under acidic and neutral conditions, respectively. It can maintain high capacity under the interference of various cations and anions. Meanwhile, this excellent selective adsorption of Ni(II) and Mo(VI) by Co/Zn-ZIF-NH 2 is revealed at the atomic level using density functional theory (DFT) calculations. This study offers a theoretical basis and experimental reference for the design and synthesis of ZIF and biomass-based composite adsorbents.
研究领域:
环境科学
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材料科学
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DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
Yuezhou Wei,Khalid A.M. Salih,Kamal Rabie,Khalid Z. Elwakeel,Yasser E. Zayed,Mohammed F. Hamza,Eric Guibal
Alginate-PEI beads are functionalized by phosphorylation and applied for the sorption of Nd(III) and Mo(VI). The successful grafting of phosphoryl groups (as tributyl phosphate derivative) is characterized by FTIR and XPS analysis, elemental analysis, titration (pH PZC ), TGA, BET and SEM-EDX analyses. The multi-functional characteristics of the sorbent (i.e., carboxylic, hydroxyl, amine and phosphate groups) contribute in the binding of metal ions having different physicochemical behaviors. The sorption of Nd(III) is strongly increased by phosphorylation, while for Mo(VI) the enhancement is rather limited. Optimum sorption occurs at pH 3–4: maximum sorption capacity reaches up to 1.46 mmol Nd(III) g −1 and 2.09 mmol Mo(VI) g −1 ; sorption isotherms are fitted by the Langmuir equation. The equilibrium is reached within 30–40 min and the kinetic profiles are simulated by the pseudo-first order rate equation. The coefficients of the effective diffusivity are close to the self-diffusivity of Nd(III) and Mo(VI) in water; as a confirmation of the limited impact of resistance to intraparticle diffusion in the kinetic control. The sorbent is selective for Nd(III) over Mo(VI) and other alkali-earth or base metals (at pH close to 2.5–3). Metals can be readily desorbed using 0.2 M HCl/0.5 M CaCl 2 as the eluent. The loss in sorption does not exceed 5% at the fifth cycle, while desorption remains complete. A series of treatments (including acidic leachate, cementation, precipitation, sorption and elution) is successfully applied for the recovery of rare earths from Egyptian ore; with enrichment in the oxalate precipitate of Nd(III), Gd(III), Sm(III) and Eu(III).
研究领域:
环境科学
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材料科学
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化学工程
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分析化学
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DOI
高影响因子
WATER SCIENCE AND TECHNOLOGY
·
2020
·Vol. 83
·期 2
·435-448
·
IF 1.638
Wu Lang,Luo Zhengwei,Jiang Hui,Zhao Zijian,Geng Wenhua
Fe 3 O 4 nanoparticles-based magnetic Mo(VI) surface ion-imprinted polymer (Mo(VI)-MIIP) was elaborated employing 4-vinyl pyridine as a functional monomer. The adsorbent preparation was confirmed by Fourier-transform infrared spectroscopy, scanning electron microscopy, energy dispersive X-ray spectrometry, X-ray diffraction, vibrating sample magnetometer, thermogravimetric analysis, and surface area analysis. Batch adsorption experiments showed that the maximum adsorption capacity of Mo(VI)-MIIP was 296.40 mg g −1 at pH 3, while that of the magnetic non-imprinted polymer (MNIP) was only 147.10 mg g −1 . The adsorption isotherm model was well fitted by the Langmuir isotherm model. The adsorption experiments revealed that Mo(VI)-MIIP reached adsorption equilibrium within 30 min, and the kinetics data fitting showed that the pseudo-second-order kinetics model suitably described the adsorption process. Mo(VI)-MIIP exhibited an excellent adsorption selectivity to Mo(VI) in binary mixtures of Mo(VI)/Cr(VI), Mo(VI)/Cu(II), Mo(VI)/ , Mo(VI)/Zn(II), and Mo(VI)/I – , with relative selectivity coefficients toward MNIP of 13.71, 30.27, 20.01, 23.53, and 15.89, respectively. After six consecutive adsorption-desorption cycles, the adsorption capacity of Mo(VI)-MIIP decreased by 9.5% (from 228.4 mg g −1 to 206.7 mg g −1 at initial Mo(VI) concentration of 250 mg L −1 ), demonstrating its reusability. Magnetic surface ion-imprinted polymer was synthesized for rapid and selective removal Mo(VI) from aqueous solution. The effects of pH value, contact time and initial concentration on the adsorption process were investigated. Mo(VI) adsorption followed the pseudo-second-order kinetics and Langmuir isotherm model. Magnetic surface ion-imprinted polymer showed high selectivity for Mo(VI) in the presence of competitive ions.
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DOI
高影响因子
CHEMOSPHERE
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2020
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IF 5.778
Jianjun Lian,Heli Wang,Hongping He,Weilin Huang,Mei Yang,Yin Zhong,Ping’an Peng
Iron sulfide (FeS) is an important scavenger for hexavalent molybdate (Mo(VI)) in an anoxic environment; it plays a crucial role in the mobilization and transformation of Mo(VI), although the underlying reaction mechanisms between Mo(VI) and FeS remain unclear. This study investigates the Mo(VI) reaction kinetics with the amorphous FeS over a pH range 5.0–9.0 and Mo’s chemical form on the FeS surface. It is found that the Mo(VI) reaction kinetics with FeS follow a pseudo first-order model, and the reaction rate constant ( k obs ) increases with a decrease in the pH value. The k obs at pH 5.0 is 0.027 min −1 , which is about 38 times higher than that at pH 9.0. The rapid Mo(VI) removal under acidic conditions is due to quick Mo(VI) transformation into stable MoS 2 and thiomolybdate (Mo V O x S y ). The amount of MoS 2 formed on the surface of FeS increases with a decrease in the pH value. Under neutral and alkaline conditions, Mo(VI) is not transformed into MoS 2 by FeS because the precipitation of iron oxy-hydroxide passivates the active sites of FeS. The study also investigates the effect of the initial dosage of FeS (20–200 mg L −1 ) and Mo(VI) (10–50 mg L −1 ) on the reaction kinetics of Mo(VI) with FeS. The results provides important information on the environmental fate of Mo(VI) in the anoxic environment containing amorphous FeS.
研究领域:
环境科学
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地球化学
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DOI
PubMed
高影响因子
POLYMER SCIENCE SERIES B
·
2016
·Vol. 58
·期 5
·495-502
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IF 0.737
Geng Jieting,Sun Yanjie,Hua Jing
Polyisoprene with relatively high content of 1,2/3,4 structure was synthesized using a novel catalyst system composed of MoO 2 Cl 2 supported by phosphorus ligand and Al(OPhCH 3 )( i -Bu) 2 as co-catalyst. The effects of phosphites, phosphates and phosphoric acid as ligands were investigated in the coordination polymerization of isoprene in the chosen catalyst system. The studied ligands significantly affected the catalytic activity of the Mo–Al catalytic active center without significant effect on the stereoselectivity. Mo(VI)-based catalyst system was proved to be highly effective in the polymerization of isoprene even at low [Al]/[Mo] ratio (10), affording polyisoprene with 1,2- and 3,4-% structural units in the range of 44.6–52.5%, high molecular weights M
n ~ 10 5 , and relatively broad molecular weight distributions ( M
w / M
n = 3.0–4.4). The effect of molar ratio of phosphorous ligand to Mo-catalyst on catalyst activity of isoprene polymerization was discussed, and the structures of Mo–phosphite complexes were preliminarily studied by IR.
研究领域:
材料科学
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催化化学
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DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2025
·
IF 7.2
Junshuo Cui,Shuang Liu,Liangyu Guo,Zhongjun Li,Zuozhen Zhang,Ying Xiong
Uniform dispersion of graphene is a prerequisite for the preparation of high-performance graphene-based composites. In this study, a new type of coupling agent which contains a thiophene center and two silanol groups (TPSi) is synthesized via amino-epoxy ring-opening reaction. The molecule shows good ability for dispersing graphene in water based on its amphiphilic feature. Dynamic light scattering (DLS) reveals that the concentration of graphene reaches 3 mg mL −1 at the weight ratio of TPSi-to-graphene of 1:1. It also stabilizes graphene well when diminishing the weight ratio to 0.5:1. By freeze-drying the dispersion, TPSi/graphene composite is prepared and it shows good adsorption performance for Mo(VI) in water. The maximum capacity can reach to 134.87 mg g −1 at pH 3 according to the Langmuir isotherm model. The composite also exhibits fast adsorption kinetics that equilibrium could be achieved within 2 h. TPSi plays a key role for the uniform distribution of graphene and improves the adsorption capability of graphene-based composite for Mo(VI) ions.
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DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2021
·
IF 7.46
Hao Lin Zou,Ling Yun Qin,Hong Qun Luo,Bang Lin Li,Nian Bing Li
Semiconducting MoS 2 obtained from the liquid-phase exfoliation is oxidized at the potentials higher than 0.65 V via applied electrochemical processes, and high-valence Mo(VI) are formed. The oxidized MoS 2 exhibits comparable performance to the electrochemical oxidation of nitrite, promoting the construction of sensors based on the assembly of nanomaterials. The signal amplification mechanism is exploited, and enhanced sensing responses are confirmed considering the strong coupling effect of Mo(VI) to nitrite. In order to optimize the sensing performance, the measurement parameters including the pH of buffer solutions, scan rates, and modification conditions are discussed. The cyclic voltammetry and chronoamperometry are successfully employed, and the oxidized MoS 2 performs satisfactory linear relationship to nitrite concentrations ranging from 1.0 μM to 386.0 μM, with the detection limit of 0.028 μM. The oxidation state and enhanced electrochemical responses of semiconducting MoS 2 as well as the developed nitrite sensing strategy inspire emerging characteristics of layered nanostructures and achieve the high potential in practical environmental and food safety monitoring.
研究领域:
材料科学
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环境科学
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分析化学
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产品关联
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2026
·Vol. 14
·期 30
·13403-13416
·
IF 7.6
Zhang Jun,Zhang Long,Zhi Fupeng,Zheng Dong,Shi Guangyue,Hou Wei,Jin Zishan,Wu Kaixuan,Yuan Doudou,Cao Lei
Efficient recovery of molybdenum(VI) and the sustainable utilization of metal-loaded spent adsorbents are important for reducing secondary pollution and promoting circular chemistry. A sodium alginate/poly(dimethylacrylamide) semi-interpenetrating polymer network hydrogel (SSP) was developed for Mo(VI) adsorption and catalytic valorization. SSP showed a Mo(VI) adsorption capacity of 108.2 mg g –1 at pH 3 and 298 K, reached equilibrium within 120 min, and retained 86.8 mg g –1 after five cycles. Mechanical testing, 10-fold scale-up preparation, and simulated high-chloride wastewater adsorption supported its practical potential. The spent Mo-loaded SSP was directly used as a supported Mo catalyst for the oxidative synthesis of 2-substituted benzimidazoles without regeneration or post-modification. Using ethanol and H 2 O 2 , 2-phenylbenzimidazole was obtained in 90.2% yield, and substituted products were obtained in 47.2-93.5% yields. Apparent TON and TOF values were 4.44–8.80 and 1.48–5.86 h –1 , respectively, with Mo leaching of approximately 0.027%. DPBF trapping and TEMP-EPR indicated that singlet oxygen was the dominant reactive species. This work establishes a Mo(VI)-specific adsorption-to-catalysis closed-loop system integrating metal removal, immobilization, and value-added organic synthesis.
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DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
Wenjing Li,Xuelin Dong,Lihua Zhu,Heqing Tang
It is urgently needed to develop highly efficient and selective adsorbents for enrichment and separation of Re(VII) from Mo(VI) to obtain metallic rhenium. By tuning cross-link of chitosan, ionic gel capsules (CSN) were prepared, which had a core-shell structure and wrapped N263 (methyl trioctyl ammonium chloride) as an extractant. After being characterized, the CSN capsules were used as a green adsorbent for separation of ReO 4 − from MoO 4 2− . It was found that the gel yielded good adsorption capacities for Re(VII) in a wide pH range from pH 2 to 12. The adsorption of Re(VII) on the gel followed the Langmuir model, exhibiting a maximum adsorption capacity of 222 mg g −1 for Re. The adsorbent showed good adsorption capacities for Mo(VI) at pH < 2, but little at pH > 3.5. Therefore, the enrichment and separation of Re(VII) from Mo(VI) could be easily achieved by using the gel adsorbent in a wide pH range from 4 to 12, showing a separation factor β Re/Mo with values of 10 3 –5 × 10 4 . A mechanism was proposed for the selective adsorption of Re(VII). The extractant N263 wrapped in the capsule core provides excellent extractive adsorption ability for Re(VII) through ion association extraction, generating ion association complex R 4 N + ∙ReO 4 − in the adsorbent. The gel shell was composed of cross-linked chitosan induced by sodium tripolyphosphate, and functioned as a blocking layer for the adsorption of Mo(VI), being possibly related to a special interaction between Mo and P as observed in the formation of phosphorus molybdenum heteropolyacid and/or the crosslinking with Mo and chitosan. The CSN gel was successfully applied to separate ReO 4 − from a practical alkaline solution.
研究领域:
环境科学
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材料科学
·
生物化学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）