COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2021
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IF 4.539
Weifeng Li,Tao Zhang,Li Lv,Yanxiao Chen,Wenxiang Tang,Shengwei Tang
A novel strategy of room-temperature synthesis of MIL-100(Fe) with organic amine as deprotonating agent was proposed. The as-prepared solid product was denoted as R-MIL-100(Fe). The material was systematically characterized via XRD , FT-IR, XPS and SEM. The effects of operation parameters such as initial fluoride concentration, reaction time, initial pH and co-existing anions on the fluoride adsorption performance of the synthesized R-MIL-100(Fe) were studied. The maximum fluoride adsorption capacity of R-MIL-100(Fe) was as high as 23.53 mg/g at 298 K in the fluoride solution. The results indicate that the adsorption process of fluorine on R-MIL-100(Fe) belongs to surface adsorption and intraparticle diffusion . An excellent fluoride adsorption performance of R-MIL-100(Fe) was observed in a wide pH range of 4–10. The co-existing anions including Cl - , NO 3 - and SO 4 2- almost had no negative effects on the adsorption performance of R-MIL-100(Fe). However, the present of CO 3 2- or HCO 3 - brought an obvious reduction of F - adsorption capacity of R-MIL-100(Fe). Thermodynamic study results illustrate that the adsorption process was an exothermic chemisorption . Chemical combination of iron and fluorine was confirmed by FT-IR and XPS. The strong combination brings the excellent F - adsorption performance of MIL-100(Fe). R-MIL-100(Fe) was successfully regenerated and recycled five cycles with an excellent regeneration ability and recyclability.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
Desalination and Water Treatment
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2015
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IF 1.173
Yumei Zhang,Lan Yang,Dongtian Wang,Tao Zhang
For resource utilization, water treatment residual sludge (WTRS) and its cerium-modified product (Ce-WTRS) were used as adsorbents to remove F− from aqueous solution. The adsorbent materials were characterized by energy dispersive X-ray, scanning electron microscope, X-ray diffraction, Fourier transform infrared, and specific surface area test techniques. Different experimental conditions such as pH, initial F− concentration, contract time, and temperature were investigated. The appropriate adsorption capacity was achieved in the pH range of 3–9. Adsorption kinetics, isotherm, and thermodynamic studies were used to illustrate the nature of F− onto adsorbents materials. Good fitting of pseudo-second-order kinetics model indicated the chemisorption nature. Further analyses of intra-particle diffusion model were carried out to determine the rate controlling step. It was found that the Langmuir and Temkin isotherm models fitted the experimental data better. The maximum adsorption capacity (qm) determined by Langmuir isotherm model was 15.45 mg/g for Ce-WTRS, 22% higher than WTRS. The negative values of ΔGθ indicated the feasibility and spontaneity of material-fluoride interaction. ΔHθ >0 for Ce-WTRS demonstrated the endothermic nature, while ΔHθ <0 for WTRS suggested an exothermic procedure. Ion exchange and complex reaction were identified as the main mechanism of fluoride adsorption.
研究领域:
环境科学
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化学工程
✓ 已验证
DOI
高影响因子
Materials
·
2024
·Vol. 17
·期 3
·766
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IF 3.1
Wei Li,Pengcheng Xie,Haiyang Zhou,Huiying Zhao,Bo Yang,Jian Xiong
In this study, tea waste was used as a raw material, and TBC (tea waste biochar) was prepared by pyrolysis at 700 °C. La(NO3)3·6H2O was used as the modifier to optimize one-way modification; the orthogonal experiment was undertaken to determine the optimal preparation conditions; and La-TBC (lanthanum-modified biochar) was obtained. The key factors for the adsorption of fluoride by La-TBC were investigated by means of batch adsorption experiments, and kinetics and isothermal adsorption experiments were carried out on the adsorption of fluoride in geothermal hot spring water. The adsorption mechanism of fluoride by La-TBC was analyzed via characterization methods such as SEM-EDS (Scanning Electron Microscope and Energy Dispersive Spectrometer), BET (Brunauer–Emmett–Teller), FTIR (Fourier transform infrared), XRD (X-ray diffraction), and so on. The results show that La-TBC had the best adsorption effect on fluoride at pH 7. The process of adsorption of fluoride follows the pseudo-second-order kinetics and Langmuir isothermal model, and the maximum theoretical adsorption quantity was 47.47 mg/g at 80 °C, while the removal rate of fluoride from the actual geothermal hot spring water reached more than 95%. The adsorption process was dominated by the monolayer adsorption of chemicals, and the mechanisms mainly include pore filling, ion exchange, and electrostatic interaction.
研究领域:
环境科学
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材料科学
✓ 已验证
DOI
PubMed
高影响因子
ENVIRONMENTAL GEOCHEMISTRY AND HEALTH
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2024
·Vol. 47
·期 1
·1-18
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IF 3.2
Gong Huichun,Ke Pingchao,Zhou Yipeng,Xu Lingling,He Guang,Jian Peng
Fluoride contamination is a serious environmental problem in lepidolite hydrometallurgy wastewater. The treatment of fluoride-bearing wastewater is challenging because of the presence of coexisting ions including lithium (Li + ), rubidium (Rb + ), silicate (SiO 3 2− ), sulfate radical (SO 4 2− ). However, aluminum-modified zeolite (Al@zeolite) with sufficient hydroxyl groups and high adaptability has unique advantages for eliminating fluoride from lepidolite hydrometallurgy wastewater. Al@zeolite was prepared on natural zeolite by an atmospheric process and then used for the adsorption of fluorine from fluoride-bearing wastewater produced by the lepidolite hydrometallurgy process. The results of material characterization confirmed the successful immobilization of aluminum within the zeolite pores and indicated the formation of zeolite-Al–OH. The zeolite host significantly enhanced the chemical stability of Al@zeolite against pH changes for a wide pH range of 2.0–10.0. The adsorbent had a surface area of 33.46 m 2 /g and demonstrated excellent capacity and selectivity for fluoride adsorption. Notably, a maximum adsorption of 98.6% was observed at a pH value of 6.0 for a duration of 20 min with a fluoride content of 20 mg/L, and the equilibrium concentration decreased to 0.4 mg/L. The results of fluorine adsorption showed that fluoride uptake onto Al@zeolite agreed well with the pseudo-second-order kinetic model and the Langmuir isotherm model. The reusability of the substance was evaluated for up to eight cycles following consecutive regeneration with 0.2 mol/L AlCl 3 . The exhausted Al@zeolite was effectively regenerated through simple alkaline treatment for recycling. The above results verified that Al@zeolite is a new kind of efficient defluoridation adsorbent for lepidolite hydrometallurgy wastewater with practical application prospects.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMOSPHERE
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2022
·
IF 8.943
Chao Ren,Hongtao Wang,Junfeng Ji,Wei Li
Calcination is an effective way to improve the F − adsorption capacity of layered double hydroxide (LDH) materials, however, a molecular scale understanding of the enhanced defluoridation capability of calcined LDHs (CLDH) is lacking. This study investigated the mechanisms of F − adsorption by CLDH using 19 F solid-state NMR, X-ray photoelectron spectroscopy (XPS), and high-resolution TEM . Under calcination process, LDH underwent three periods: surface dehydration below 200 °C, structural dehydroxylation at 200–400 °C, and release of interlayer carbonate groups above 400 °C. Additionally, XPS and XRD characterization showed that CLDH could not recover to the original structural symmetry even after rehydration and reconstitution. The F − affinity was greatly enhanced for the calcined LDH, especially at high pH. At pH 10, the adsorption capacity could reach 22.0 mg F − /g for CLDH (500 °C calcined), about 6 times larger than that of LDH. The XRD analyses revealed that the F-adsorbed CLDH had a poorer crystalline degree as the calcination temperature increased, consistent with the TEM observation of abundant defects and Mg/Al oxides on the CLDH sheets. 19 F solid-state NMR spectra of the CLDH after F − adsorption showed that the formation of surface Al–F is the predominant F − adsorption mode at pH 7, whereas the Mg–F local coordination mode is the pronounced F − adsorption mechanism under alkaline conditions (pH 10). The present study provided a comprehensive understanding of CLDH in F − adsorption and suggested that calcination is a promising treatment for promoting the efficacy of polluted anion scavenging.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2019
·
IF 7.65
Yali Guo,Xu Xing,Yanan Shang,Baoyu Gao,Lei Zhang,Qinyan Yue,Li Qian,Zihang Wang
To insight into the selective adsorption mechanism of fluoride in the bimetallic system, Fe-La or Al-La composites were comparatively embedded onto the cellulose/graphene hybrids (CG hybrids) to fabricate the Fe-La@CG hybrids or Al-La@CG hybrids for fluoride uptake with existing phosphate. The results showed that Al-La@CG hybrids were mainly in the amorphous nature, while Fe-La@CG hybrids have the identical diffraction peaks as compared with those of hydrated lanthanum oxides (HLO) and hydrated iron oxides (HFO). Fluoride capture by Al-La@CG and Fe-La@CG hybrids followed the similar tendencies with the pH altering, but the adsorption performance of Al-La@CG hybrids was better than that of Fe-La@CG hybrids at the same pH levels. Adsorption of fluoride onto Al-La@CG hybrids exhibited less sensitivity and high selectivity with existing phosphate as compared with that of Fe-La@CG hybrids, which further indicated that the Al-La@CG hybrids were more preferable for fluoride adsorption. The fraction areas of La-F and Al-F accounted for 79.1 % and 20.9%, which indicated that the fluoride onto the Al-La@CG hybrids was mainly based on the La species. Similarly, La-F in exhausted Fe-La@CG hybrids accounted for 55.6%, higher than that (44.4%) of Fe-F.
研究领域:
材料科学
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环境科学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Yu Pan,Xun Liu,Meng Zhang,Qi Han,Yufei Shu,Mengxia Wang,Bei Liu,Zhongying Wang
The presence of excess fluoride ions in drinking water has raised widespread concerns, necessitating the development of effective methods for its removal. Cerium dioxide (CeO 2 ) holds promise as a selective adsorbent for fluoride ions, due to its exceptional affinity for fluoride and stability across a wide pH range. However, the impact of intrinsic properties of CeO 2 on its adsorption characteristics and mechanisms remains unclear. In this study, we prepared a range of CeO 2 materials with diverse intrinsic properties by adjusting the annealing temperature and atmosphere. Through a series of characterization techniques, we discovered a correlation between the content of oxygen vacancies, Ce(III) species, and surface hydroxyl groups (–OH), all of which decreased simultaneously with increasing air annealing temperature. With respect to the adsorption performance, the highest fluoride adsorption capacity of 111.1 mg g −1 was observed in un-CeO 2 , representing the nanomaterials with the highest oxygen vacancies. This capacity gradually decreased to 29.1 mg g −1 in 800-CeO 2 . Following fluoride adsorption, the oxygen vacancy density, Ce(III) content, and surface –OH content of all CeO 2 materials decreased. When CeO 2 materials were annealed in H 2 for 1 h, the F − adsorption density increased due to the formation of more oxygen vacancies and surface –OH. Based on our findings, we conclude that oxygen vacancies play a critical role in determining whether fluoride ions can successfully exchange with surface –OH groups and enter the crystal lattice of CeO 2 , which significantly affects the adsorption performance. The pivotal role of oxygen vacancies, as proposed in this study, provides a valuable direction for future research aimed at enhancing the fluoride adsorption performance of CeO 2 .
研究领域:
材料科学
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环境科学
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化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2025
·
IF 9.5
Shiyu Sun,Xin Huang,Xue Bai,Qian Wu,Bin Lu,Zijian Zhou,Na Wang,Ting Wang,Hongxun Hao
The rapid development of the fluorine chemical industry has resulted in serious fluoride pollution in water sources and the cost-effective removal of fluoride remain a critical challenge. In this study, PTiO2@UiO-66-NH2, a nanocage material with ternary amino cryptands cavities and Ti/Zr dual-metal sites, was synthesized through a stepwise assembly process involving: (i) oxidative polymerization of aniline on TiO2 nanotubes, followed by (ii) in-situ solvothermal growth of UiO-66-NH2. The material exhibits a fluoride adsorption capacity of 143.66 mg/g (298.15 K, pH = 3), surpassing most reported adsorbents, and maintains >89% efficiency over 5 regeneration cycles. Structural characterization (TEM, XPS, FTIR) confirms the unique ternary amino cryptands formed by amino groups, while DFT calculations reveal that their self-adaptive electron dispersion effect reduces the energy barrier for fluoride adsorption on metal sites by 49% (from 4.36 eV to 2.23 eV), enabling synergistic enhancement. This work provides a new strategy for designing high-performance adsorbents through electronic-structure-driven active-site cooperation.
研究领域:
环境科学
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材料科学
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纳米技术
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化学工程
·
无机化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）