ENVIRONMENTAL GEOCHEMISTRY AND HEALTH
·
2024
·Vol. 47
·期 1
·1-18
·
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
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
NanoImpact
·
2025
·
IF 5.5
Shihao Zhao,Ruihao Xu,Xiangying Liu,Yifan Wang,Yanji Jiang
Perfluorooctanoic acid (PFOA) and perfluoropentanoic acid (PFPeA), as important components of perfluorinated compounds (PFAS), are not only ecologically hazardous, but also have surfactant properties that can alter the transport behavior of polytetrafluoroethylene (PTFE) in porous media. In this experiment, the effect of PFAS on the transport of PTFE in porous media under different pH, ionic strength (IS) and ion valence states was studied. The results showed that the recovery rate of PTFE decreased gradually with the decrease of pH and the increase of IS and ion valence states. When the above conditions change, the double electron layer on the microplastic surface is compressed, the absolute value of zeta potential decreases, the repulsion between each other decreases, and aggregation and deposition are more likely. In addition, it was found that the recovery rate of PTFE co-transported with long chain PFOA was higher than that of short chain PFPeA. This phenomenon may be caused by the adhesion ability of PFOA with long carbon chain on the surface of PTFE is greater than that of PFPeA with short carbon chain. On the other hand, PFAS with different carbon chain lengths produce different spatial site resistance effects after binding with particles, and the spatial site resistance produced by the long-chain PFOA is larger than that of the short-chain PFPeA, leading to a decrease in particle-to-particle aggregation and a better transport effect. This study will help to understand the effects of PFAS with different carbon chain lengths on the transport of microplastics in porous media, as well as the transport rule of PTFE under different conditions, and provide reference value for the calculation of its flux in soil.
研究领域:
环境科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Environmental Technology & Innovation
·
2024
·
IF 6.7
Yongjia Lei,Hongyu Zeng,Ravi Naidu,Dong Tian,Li Zhao,Mei Huang,Jinsong He,Jianmei Zou,Shihuai Deng,Li Sun,Fei Shen
Due to the synergistic contribution, dual-frequency ultrasound can significantly enhance the degradation of organic contaminants, but the effects of different frequency combinations have not been clarified and need to be explored. In this study, several frequency combinations were designed firstly both in experimental exploration and numerical simulation within the dual-frequency ultrasound coupling persulfate (PS) system to investigate the effect of frequency combinations on the degradation of perfluorooctanoic acid (PFOA). The monitoring parameters included the defluorination percentage and the simulated maximum expansion ratio ( R max / R 0 ). The simulated maximum expansion ratios in different frequency combinations showed a high correlation with their defluorination results, indicating that the discrepancy in defluorination effects of different frequency combinations was mostly attributed to their various maximum expansion ratios. Additionally, various maximum expansion ratios could result in different maximum solution temperatures, and the increase in temperature was found positive for PFOA defluorination in this study. In addition, the synergistic parameters that affected the maximum expansion ratio were analyzed, including the phase difference, frequency ratio, and frequency value. The obtained results showed that the maximum expansion ratio varied with different phase differences, and the frequency ratio could affect the variation trend. For the same fundamental frequency, the larger the frequency ratio, the smaller the maximum expansion ratio. Under the same phase difference and frequency ratio, the larger the frequency value, the lower the cavitation.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Energy Materials
·
2021
·
IF 6.024
Jun Ban,Xingxing Jiao,Yangyang Feng,Jing Xue,Cheng He,Jiangxuan Song
Lithium/fluorinated carbon (Li/CFx) batteries have received widespread attention due to their high specific energy density. However, the development of Li/CFx primary batteries is seriously hampered owing to the low electrical conductivity and poor wettability against the fluorinated carbon electrolyte. Here, we report a CFx-compatible fluorinated ether-containing electrolyte for all-temperature high-energy-density Li/CFx primary batteries. Specifically, a CFx-philic 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether (TTE) is introduced to the carbonate-based electrolyte as a cosolvent. Benefiting from the low viscosity and low freezing point of TTE, the conductivity and wettability are drastically improved, contributing to a lowered charge-transfer resistance. Thus, the modified electrolyte with TTE endows Li/CFx batteries with high energy density of 850 Wh kg–1 at 25 °C and 745 Wh kg–1 at 55 °C under the current density of 5000 mA g–1, accompanied by high power density of 9931 and 10046 W kg–1, respectively. Even at the freezing temperature of −50 °C, Li/CFx batteries can still exhibit a high middle value of voltage of 1.91 V, and the discharge capacity is 299 mAh g–1 at 100 mA g–1. The improvement of electrochemical performance over a wide temperature range from −50 to 55 °C has greatly expanded the application of Li/CFx batteries.
研究领域:
材料科学
·
电化学
·
能源存储
✓ 已验证
DOI
高影响因子
LIQUID CRYSTALS
·
2016
·
IF 2.244
Dingqian Shi,Kun Hu,Pei Chen,Aiai Gao,Weisong Du,Ran Chen,Xinbing Chen,Zhongwei An
Fluorine is widely used as a lateral substituent to modify the physical properties of liquid crystals. Here, laterally monofluorinated compounds, 2-(4ʹ-alkoxy-2-fluorobiphenyl-4-yl)-benzoxazole derivatives (nPPF(2)Bx) bearing different substituents (H, CH3, NO2, coded as nPPF(2)BH, nPPF(2)BM and nPPF(2)BN, respectively) at 5-position, were synthesised and characterised. It is interesting to note that these only display enantiotropic nematic mesophases with mesophase ranges of 12–28°C and 13–45°C on heating and cooling for nPPF(2)BH, 46–97°C and 62–120°C for nPPF(2)BM and 82–108°C and 87–113°C for nPPF(2)BN, which are very different from the corresponding monofluorine-substituted analogue (compounds I) with enantiotropic smectic or smectic/nematic mesophases. The enhanced nematic mesophase is attributed to the reduced π–π interaction/conjugation resulting from the twisted structure of the molecule caused by the introduction of a fluorine atom into the inter-ring of the biphenyl unit. These results suggest that modification of the monofluorine substituent position is an effective method to improve the nematic mesophase in benzoxazole-liquid crystals.
研究领域:
材料科学
·
有机化学
✓ 已验证
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2024
·
IF 8.2
Xiaoyuan Wang,Yinchuan Lv,Xin Qiang,Shumin Liang,Ruosi Li,Jing Zhan,Jiaying Liu
The disruption of per- and polyfluoroalkyl substances (PFASs) on bile acid (BA) homeostasis has raised public concerns, making the evaluation of their effects and underlying mechanisms a high priority. Although the use of perfluorooctanoic acid (PFOA) has been restricted, it remains a widespread legacy PFAS in the environment. Concurrently, the use of its prevalent short-chain alternative, perfluorobutanoic acid (PFBA), is increasing, yet the toxicity assessment of PFBA remains inadequate. In this study, C57BL/6N mice were exposed to PFOA and PFBA (0.4 or 10 mg/kg body weight) by gavage for 28 days. The results showed that both PFOA and PFBA significantly increased hepatic weight, although PFBA exhibited lower bioaccumulation than PFOA in the liver. Targeted metabolomics revealed that PFOA significantly decreased total BA levels and altered their composition. Conversely, PFBA, without significantly altering total BA levels, notably changed their composition, such as increasing the proportion of cholic acid. Further investigations using in vivo and in vitro assays suggested that PFOA inhibited the expression of Cyp7A1, a key BA synthetase, potentially via PPARα activation, thereby reducing BA levels. In contrast, PFBA enhanced Cyp7A1 expression, associated with the inhibition of intestinal Farnesoid X receptor-fibroblast growth factor 15 (FXR-FGF15) pathway. This study evaluated the differences in the BA-interfering effects of PFOA and PFBA and shed light on the potential mechanisms, which will provide new insights into the health risks of legacy PFASs and their alternatives.
研究领域:
毒理学
·
环境健康
·
代谢组学
·
分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Yongsheng Niu,Lixin Sun,Haiying Fu,Qiang Dou,Yuan Qian,Qingnuan Li
Molybdenum-99 ( 99 Mo) is one of the most important radionuclides for nuclear medicine. This isotope of molybdenum is mainly produced as a result of fission and decay processes occurring in nuclear reactors. Molten salt reactors (MSRs), a unique reactor with the fuel dissolved in a molten salt , have attracted attention as a source of 99 Mo. In this work, the feasibility of fluoride volatility process as a potential technique for selective extraction of trace amount of 99 Mo from fuel salt in the form of volatile MoF 6 by nitrogen trifluoride (NF 3 ) is illustrated. The results showed that in the case of using LiF-BeF 2 -ZrF 4 -UF 4 -MoF 3 (64.4–29.7–5.0–0.5–0.4 mol.%) molten salt as the simulated fuel salt, MoF 3 reacted with NF 3 to form MoF 6 at or above 570℃, while the conversion of UF 4 to volatile UF 6 required higher temperatures (≥650℃), when both exposed to 20 % NF 3 /Ar mixture. Based on above “cold” experiments, fluoride volatility process in LiF-BeF 2 -ZrF 4 molten salt containing irradiated UF 4 was carried out, and the extraction rate of 99 Mo was determined by detecting the change of its γ activity in the molten salt. The results indicated that 99 Mo could be extracted from the molten salt containing a quantity of uranium with the extraction rate of 98 % under current experimental conditions, and the content of uranium in collected 99 Mo product was only 0.9 wt%.
研究领域:
核医学
·
化学工程
·
核能工程
✓ 已验证
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2017
·
IF 6.065
Shuyan Zhao,Tao Zhou,Bohui Wang,Lingyan Zhu,Meng Chen,Dandan Li,Liping Yang
Perfluorooctane sulfonamide (PFOSA) is a precursor of perfluorooctane sulfonic acid (PFOS) and can be broken down to PFOS in environment and biota. In the present work, PFOSA was spiked in soil and its biodegradation in soil, uptake and metabolism in wheat ( Triticum aestivum L.) and earthworms ( Eisenia fetida ) were investigated. The results indicated that PFOSA could be biodegraded to highly stable PFOS, which has the same perfluorinated carbon chain length as PFOSA, by microbes in soil. PFOSA could be taken up by wheat root and earthworm from soil with higher bioaccumulation ability than PFOS. In both wheat and earthworms, PFOSA also degraded to PFOS. However, other shorter-chain perfluoroalkane sulfonates (PFSAs), including perfluorohexane sulfonate (PFHxS) and perfluorobutane sulfonate (PFBS), were observed in wheat, but not in soil and earthworms, suggesting that wheat displayed distinctly different degradation mechanisms to PFOSA from soil microbes and earthworms.
研究领域:
环境科学
·
植物学
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2020
·
IF 6.182
Wenfeng Han,Hong Yang,Linzhe Wang,Bing Liu,Xiaoli Wei,Aimin Chen,Weiyu Song,Haodong Tang,Ying Li
Aluminum fluoride layers (AlFx) were prepared by the in situ etching of Ti 3 AlC 2 with 1,1-difluoroethane at elevated temperatures. During etching, Ti layers were fluorinated to stable TiF 3 interacting with C to confine the Al species and sublimable TiF 4 . Al layers were fluorinated to unsaturated AlFx with relatively weak Lewis acidity. Due to the sublimation of TiF 4 , more AlFx acting as the main active centers were exposed to the reactants, and the surface areas of the confined-AlFx were increased, which contributed to the enhanced activity of the catalyst. The evaluation of the dehydrofluorination reaction showed that confined-AlFx layers presented higher reaction rate than F-γ-Al 2 O 3 and AlF 3 . Besides, it was unexpected that TiF 3 also exhibited activity for the reaction, even though the activity was much lower than confined-AlFx. Finally, the experimental results were confirmed by DFT calculations.
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
ADVANCED ENGINEERING MATERIALS
·
2021
·Vol. 23
·期 5
·2001252
·
IF 3.862
Dawei Zheng,Tianwei Huang,Bing Xu,Xu Zhou,Yaofeng Mao,Lin Zhong,Bing Gao,Dunju Wang
The development of 3D printing technology provides a new idea for the application of energy-containing materials as functional reactive materials, which helps Al–F high-energy materials to achieve customized performance and structure, so that energy transmit can be targeted. A high fuel-load ink (up to 90 wt%) based on Al-polytetrafluoroethylene (PTFE) is designed and fabricated using fluororubber (FR) as a binder. The content of FR is directly related to the mechanical properties of ink, and the customized structure from the uniform and stable deposition can be obtained by adjusting the content of FR (10–20 wt%). Under the display of high-speed photography, the ink shows a strong stability in combustion performance, which is conducive to realize the performance customization of the ink in the application. To better understand the combustion mechanism, the thermal properties and combustion process are analyzed in brief through thermal analysis and the combustion snapshots.
研究领域:
材料科学
·
能源工程
✓ 已验证
产品关联
DOI
高影响因子
Surfaces and Interfaces
·
2024
·
IF 5.7
Peng Liu,Linshan Wu,Xiulin Huang,Zhiguang Guo
Membrane materials are widely used in the treatment of oily wastewater. In this work, hybrid nanofibrous membranes of polyacrylonitrile (PAN) and polytetrafluoroethylene-hexafluoropropylene (PVDF-HPF) were prepared by electrospinning and cured at high temperature. Subsequent hydrothermal treatment to grow Mg/Al-LDHs and polymerization of tannic acid (TA) on the surface yielded WPPLT membranes. SEM and EDS tests showed that the WPPLT membranes had a uniform compositional distribution. AFM tests showed that the hydrothermal and tannic acid treatments increased the roughness of the membranes and imparted a superhydrophilicity to the membranes. Separation tests of the emulsion showed that the separation efficiency was above 99 % with stable flux due to the fine pore size of the nanofiber membrane and the positive charge effect of the LDHs. Mechanical tensile tests showed that the tensile strength of the WPPLT membrane was 4.1 MPa, which was 89 % higher relative to the electrospinning membrane. Finally, the synergistic effect of LDHs and tannic acid under UV irradiation achieved more than 90 % degradation efficiency of methylene blue (MB). The present work provides new insights to improve the mechanical properties of nanofiber membranes, which helps the membranes to be used in more complex environments and enhances the prospect of their application in oil and water pollution.
研究领域:
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2017
·Vol. 7
·期 37
·22810-22817
·
IF 3.108
Zhenhua Li,Jingsong Liu,Ying Yuan,Enzhu Li,Fu Wang
In this work, fluoride-functionalized glass fiber (F-GF) was prepared, in which glass fiber (GF) was modified with γ-methacryloxy propyltrimethoxy silane (γ-MPS), and then reacted with 2,2,2-trifluoroethyl methacrylate (TFEMA). Subsequently, PTFE/glass fiber microwave composites were prepared by incorporating 5 wt% of the GF, γ-MPS modified GF (M-GF) or F-GF into PTFE. The effect of F-GF on the mechanical and dielectric properties, as well as moisture absorption and coefficient of thermal expansion of the composites were investigated. The results show that fluorine is successfully grafted onto the surface of GF through –CF3 group, and F-GF forms a dense and compact interfacial structure with PTFE. The mechanical properties of PTFE/F-GF, including tensile strength (38.53 MPa) and elongation (226.82%), are obviously higher than those of PTFE/M-GF (34.73 MPa and 179.50%, respectively) and PTFE/GF (34.82 MPa and 174.33%, respectively). In addition, the PTFE/F-GF composite shows improved density (2.174 g cm−3), dielectric constant (2.18), and decreased dielectric loss (0.0009), moisture absorption (0.008%) and temperature coefficient of dielectric constant (−18.6 ppm per °C). The conclusions demonstrate that the method of surface fluorination of glass fibers offers promising application in PTFE based microwave materials.
研究领域:
材料科学
·
复合材料
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）