Journal of Hazardous Materials Letters
·
2023
·
IF 0
Ying Lyu,Baohua Wang,Mark L. Brusseau
The impact of chain length on the retention and transport of perfluorocarboxylic acids (PFCAs) in a quartz sand was investigated. Short-chain (C4–C7: PFBA, PFPeA, PFHxA, PFHpA) and long-chain (C8–C10: PFOA, PFNA, PFDA) PFCAs were selected as a representative homologous series. Miscible-displacement transport experiments were conducted under saturated conditions to characterize the magnitudes of sorption mediating retention and transport. Quantitative-structure/property-relationship (QSPR) analysis was applied to characterize the influence of molecular size on sorption. The transport of the long-chain PFCAs exhibited greater retardation than the short-chain PFCAs. The log of the equilibrium sorption coefficient ( K d ) exhibited a biphasic relationship with carbon number and molar volume, with the magnitude of measured sorption for the short-chain PFCAs significantly greater than would be predicted using the QSPR regression developed for the long-chain PFCAs. This is consistent with batch-measured data reported in the literature, and likely reflects the relative influence of different sorption mechanisms for the short-chain vs long-chain PFCAs.
研究领域:
环境科学
·
化学
✓ 已验证
DOI
CHEMICAL ENGINEERING JOURNAL
·
2018
·
IF 6.735
Jiaoqin Liu,Chenguang Li,Ruijuan Qu,Lianhong Wang,Jianfang Feng,Zunyao Wang
Hydroperfluorocarboxylic acids (H-PFCAs) have attracted worldwide attention for their potential use as alternatives to perfluorocarboxylic acids (PFCAs). Decomposition of these chemicals is of great significance due to their possible environmental risks. In this work, the photodegradation of typical H-PFCAs (HC n F 2n COOH, n = 4, 6, 10) in water by a 500 W mercury lamp was systematically examined. We found that the photodegradation of H-PFCAs all followed pseudo-first-order kinetics, and the photoreactivity increased with carbon chain length. The degradation pseudo-first-order rate coefficients of H-PFCAs were slightly slower than the corresponding PFCAs. The decomposition efficiency of HC 10 F 2 COOH was enhanced by lowering pH, but inhibited by the presence of humic acid. Three common inorganic ions showed inhibitory effect on HC 10 F 2 COOH photodegradation, with the order of NO 3 − > CO 3 2− > HCO 3 − . This is because these anions have different light absorption, making less light available for compound degradation. As a photosensitizer, Fe 3+ had an obvious promoting effect on the reaction. According to the products identified by mass spectrometry analysis, decarboxylation, defluorination and elimination reaction were mainly involved in the photodegradation of HC 10 F 2 COOH. Toxicity predictions by ECOSAR program showed that photolysis can reduce the aquatic toxicity of HC 10 F 2 COOH. This work could provide useful information for developing a simple and effective technology to treat H-PFCAs in water.
研究领域:
环境科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
·
2020
·Vol. 125
·期 13
·e2019JD032182
·
IF 3.821
Shumin Cheng,Lin Du,Christian George
Sea surface microlayers (SMLs) play an important role in the transport and fate of surfactants from both anthropogenic and biogenic sources. The formation of sea spray aerosols (SSAs) at the SML has been recognized as a critical pathway for the entry of surfactants into the atmosphere. Perfluorocarboxylic acids (PFCAs) have become increasingly concerning as a class of emerging organic pollutants, having high enrichment in surface seawaters due to their remarkable surface activity. Using artificial seawater coated by extensively existed surfactants, including stearyl alcohol (C18OH) and stearic acid (SA) as simplified models of the SML and fresh SSAs, the interfacial behaviors of soluble and insoluble PFCAs were examined. Information about lateral packing and chain conformation of films was obtained by means of Langmuir trough and infrared reflection-absorption spectroscopy (IRRAS). Perfluorooctanoic acid (PFOA) dissolved in aqueous subphases was found to be incorporated into lipid monolayers via alterations in surface pressure-area (π-A) isotherms. With negligible solubility, perfluorotetradecanoic acid (PFTA) formed condensed mixed monolayers with other lipids at the air-water interface. The mixed monolayers of C18OH/PFTA and SA/PFTA were expanded by the addition of sea salts into the pure water subphase. Compared with the π-A isotherms of SA/PFTA, decreased molecular areas were observed for those of C18OH/PFTA. This research suggests that PFCAs can be incorporated into air-water interfaces by acting as film-forming materials. The introduction of PFCAs will alter the surface properties and thus the atmospheric fate and behavior of SSAs and SMLs. Key Points Both soluble and insoluble perfluorocarboxylic acids can be incorporated into air-water interfaces by acting as film-forming materials Intermolecular interactions between fluorinated and nonfluorinated alkyl chains can affect interfacial molecular arrangements Alterations in surface packing warrant further discussion on implications for atmospheric processes from aqueous interfaces
研究领域:
环境科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
WATER RESEARCH
·
2016
·
IF 5.991
Ruijuan Qu,Jiaoqin Liu,Chenguang Li,Liansheng Wang,Zunyao Wang,Jichun Wu
Decomposition of perfluorocarboxylic acids (PFCAs) is of great significance due to their global distribution, persistence and toxicity to organisms. In this study, the photodegradation of a series of PFCAs (∼C2 C12) in water by a medium-pressure mercury lamp was experimentally and theoretically examined. We found that photolysis of PFCAs all follow pseudo-first-order kinetics with the rate constant ( k app ) increasing with carbon chain lengths, except for trifluoroacetic acid (TFA) which cannot be degraded by the polychromatic irradiation. Product analysis showed that the PFCAs were mainly decomposed into shorter carbon chain length PFCAs in a stepwise manner, with the accumulation of TFA and fluoride ions as the end products. Moreover, a small amount of perfluoroolefins (C n F 2n ) was determined as gas-phase products. Wiberg bond order calculations confirmed the cleavage of the C C bond between carboxylic carbon and the adjacent carbon as the first reaction step, and density functional theory-based calculations revealed that k app value is correlated with some molecular structural parameters. In the case of mixture irradiation, the evolution profiles of individual PFCAs were different from that in single-component systems, due to the dynamic balance between production and degradation. This work reveals the main molecular descriptors controlling the degradation rate of different PFCAs species, and improves the general understanding on the photodegradation mechanisms, which will provide useful information for future researches.
研究领域:
环境科学
·
化学
✓ 已验证
DOI
PubMed
高影响因子
Journal of Environmental Sciences
·
2012
·
IF 1.66
Baoxiu Zhao,Mou Lv,Li Zhou
Perfluorooctanoic acid (PFOA) is a new-found hazardous persistent organic pollutant, and it is resistant to decomposition by hydroxyl radical (HO) due to its stable chemical structure and the high electronegativity of fluorine. Photocatalytic reduction of PFOA with β-Ga 2 O 3 in anoxic aqueous solution was investigated for the first time, and the results showed that the photoinduced electron (e − cb ) coming from the β-Ga 2 O 3 conduction band was the major degradation substance for PFOA, and shorter-chain perfluorinated carboxylic acids (PFCAs, C n F 2n+1 COOH, 1 ≤ n ≤ 6) were the dominant products. Furthermore, the concentration of F − was measured by the IC technique and defluorination efficiency was calculated. After 3 hr, the photocatalytic degradation efficiency was 98.8% and defluorination efficiency was 31.6% in the presence of thiosulfate and bubbling N 2 . The degradation reaction followed first-order kinetics ( k = 0.0239 min −1 , t 1/2 = 0.48 hr). PFCAs (C n F 2n+1 COOH, 1 ≤ n ≤ 7) were detected and measured by LC-MS and LC-MS/MS methods. It was deduced that the probable photocatalytic degradation mechanism involves e − cb attacking the carboxyl of C n F 2n + 1 COOH, resulting in decarboxylation and the generation of C n F 2n + 1 . The produced C n F 2n + 1 reacted with H 2 O, forming C n F 2n + 1 OH, then C n F 2n + 1 OH underwent HF loss and hydrolysis to form C n F 2n+1 COOH.
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
SCIENCE OF THE TOTAL ENVIRONMENT
·
2020
·
IF 6.551
Yufei Zhou,Manman Xu,Dahong Huang,Lei Xu,Mingchuan Yu,Yunqing Zhu,Junfeng Niu
This work presented a three-dimensional (3D) hierarchically microporous biochar (HMB) via molten alkali treatment that achieved efficient adsorption of perfluorinated carboxylic acids (PFCAs), which was a significant environment concern due to the global distribution and potential health risks. The systematic optimization of fabrication process rendered the HMB large surface area and uniform microporous structure, leading to a high adsorption capacity and adsorption rate of 1269 mg/g and 197 mg/(g·min), respectively, when perfluorooctanoic acid (PFOA) was as a representative. The adsorption mechanisms were explored via controlling the interaction between PFCAs and the HMB900-2.4. Specifically, hydrophobic effect was verified by the enhanced adsorption performance with the increase of the PFCAs homologues hydrophobicity . The observed highly pH-dependent adsorption capacity additionally suggested the dominant contribution of electrostatic interaction. For long-chain PFCAs (C n F 2n+1 COOH, n > 5), the HMB900-2.4 presented a high removal efficiency (> 90%) within 30 min. Even for short-chain PFCAs (C n F 2n+1 COOH, n = 4–5), the removal efficiency reached to over 60%. The synthesized HMB900-2.4 exhibited high stability during recycling experiments and superior performance over commercial adsorbents, suggested a promise of utilizing it to remove PFCAs from wastewater.
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
CHEMICAL ENGINEERING JOURNAL
·
2016
·
IF 5.31
Jiye Huang,Xi Wang,Zhaoqi Pan,Xukai Li,Yu Ling,Laisheng Li
Perfluorooctanoic acid (PFOA) could be efficiently degraded by the combined process of photocatalysis and ozonation, its degradation intermediates were fluoride ions and short-chain perfluorocarboxylic acids (PFCAs) including C 6 F 13 COOH, C 5 F 11 COOH, C 4 F 9 COOH, C 3 F 7 COOH and C 2 F 5 COOH. After 4 h reaction time, its degradation efficiency was 99.1% and defluorination ratio only reached to 44.3%. The degradation mechanism of PFOA by photocatalytic ozonation was proposed and found to be similar to Photo-Kolbe reaction: PFOA anion was degraded to produce PFOA radical by a direct electron transfer from its carboxyl group to photo-generated hole (h + ). Then PFOA radical was decarboxylated to produce perfluoroheptyl radical, and then be oxidized to form C 7 F 15 OH by hydroxyl radical ( OH) which was produced from ozone trapping photo-generated electron. Because of its thermal instability, C 7 F 15 OH would be converted to C 6 F 13 COF, which was further hydrolyzed to generate C 6 F 13 COO − . Therefore the combined process of photocatalysis and ozonation was efficient for PFOA degradation.
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
Journal of Materials Chemistry A
·
2025
·
IF 9.5
Xu-Qin Ran,Can Zhu,Qian-Ying Mao,Shu-Ting Xu,Shuangping Liu,Peng Gu,Yun Jiang,Xiu-Ping Yan,Hai-Long Qian
Advancements of covalent organic frameworks (COFs) in the field of adsorption and extraction are always limited by their non-uniform and irregular aggregated morphology. Herein, we pioneer the preparation of monodisperse COFs with regular shape and further explore their adsorption and extraction capability. As proof of concept, a new monodisperse fluorinated 3D COF named as M-TAM-TFTA, featuring a nonpolar structure and uniform size and shape, is selected as the model COF for adsorption and extraction of perfluorocarboxylic acids (PFCAs). M-TAM-TFTA, consisting of tetra(4-anilyl)methane and 2,3,5,6-tetrafluoroterephthalaldehyde, exhibits larger adsorption capacity (554.9 mg g-1) and faster adsorption kinetics (5 min) compared to the same composition aggregated 3D COF A-TAM-TFTA as well as diverse reported materials. This remarkable adsorption performance of M-TAM-TFTA for PFCAs is proved to be dominantly caused by its lower mass transfer resistance structure and multiple specific interactions including F-F, hydrophobic, electrostatic and H-bonding interactions. The M-TAM-TFTA is further applied to develop a probe nanoelectrospray ionization mass spectrometry (PESI-MS) method for direct and precise determination of PFCAs with a wide linear range (0.5 - 5000 ng L-1) and low limits of detection (0.08 - 0.46 ng L-1). This study provides robust support for the great potential of monodisperse COF as adsorbent for treatment of contaminant in complex samples.
研究领域:
材料科学
·
环境科学
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
TALANTA
·
2024
·
IF 5.6
Gang Li,Yahan Cui,Xiaonan Yang,Xuelian Xin,Hongyuan Yan,Dandan Han
It is extremely significant while challenging to accurately detect low-levels of perfluoroalkyl carboxylic acid compounds (PFCAs) in environmental water. Herein, adopting perfluorotetradecanoic acid as the dummy template, selective molecularly imprinted composites (CNTs@ILs@MIPs) grafted carbon nanotubes integrating hydrophilic ionic liquids were successfully prepared via surface imprinting and dummy-template imprinting techniques. The obtained CNTs@ILs@MIPs were applied as selective extraction adsorbent for specifically extract PFCAs in environmental water coupled with gas chromatography-mass spectrometry quantification. Detailed studies were conducted on the main preparation parameters and extraction conditions. The CNTs@ILs@MIPs displayed excellent adsorptivity , and the established method exhibited low LODs (0.60–1.64 ng L −1 ), wide linearity with R 2 above 0.9994, and satisfactory adsorption recoveries (80.5–112.5%) for seven PFCAs. This proposed method provides a new applicable approach for the detection of targeted pollutants in environmental water by utilizing the high affinity and recognition ability of molecularly imprinted carbon nanotube functional materials modified with ionic liquids.
研究领域:
环境科学
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
BIODEGRADATION
·
2021
·Vol. 32
·期 1
·99-112
·
IF 3.909
Qiao Weichuan,Miao Jiahui,Jiang Hongmei,Yang Qiwen
Perfluoroalkyl carboxylates (PFCAs) is toxic to the environment and human health. However, the degradation characteristics of fluorotelomer alcohols (FTOHs), precursors of PFACAs biodegradation, in the sludge during aerobic composting remain unclear. In this study, the degradation characteristics of 6:2 FTOH in sewage sludge by composting were researched and the influences of 6:2 FTOH on the composting process and microbial communities of the sludge were evaluated. After 52 days of composting, 6:2 FTOH retained only 0.73% of its original concentration, and its half-life was less than 1 d; 6:2 FTOH was degraded finally to perfluorohex unsaturated acid, perfluoropentanoic acid, 5:3 polyfluorinated acid (FTCA), 4:3 FTCA, and perfluorobutanoic acid through two pathways; and 6:2 FTCA and 6:2 fluorotel unsaturated acid were the intermediate products. Notably, dosing with 6:2 FTOH affected the composting process of sewage sludge. Additionally, 50 mg/kg 6:2 FTOH resulted in a decrease in the microbial richness and diversity of sludge compost. When compared with the compost without 6:2 FTOH, the proportion of Proteobacteria had increased, and the proportion of Firmicutes had decreased as the concentration of 6:2 FTOH increased. The negative effect of a dosage of 50 mg/kg 6:2 FTOH was more obvious than the effect of other treatments. This study expanded our understanding of the risk of sludge contaminated by 6:2 FTOH being used as a fertilizer after composting.
研究领域:
环境科学
·
废物管理
·
微生物学
✓ 已验证
DOI
PubMed
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2022
·
IF 10.753
Ying Lyu,Baohua Wang,Xinqiang Du,Bo Guo,Mark L. Brusseau
The impact of chain length on air-water interfacial adsorption of perfluorocarboxylic acids (PFCAs) during transport in unsaturated quartz sand was investigated. Short-chain (C4-C7: PFBA, PFPeA, PFHxA, PFHpA) and long chain (C8-C10: PFOA, PFNA, PFDA) PFCAs were selected as a representative homologous series. Surface tensions were measured to characterize surface activities of the selected PFCAs. Miscible-displacement column experiments were conducted for each of the PFCAs to characterize the magnitudes of air–water interfacial adsorption under transport conditions. The transport of the long-chain PFCAs exhibited greater retardation than the short-chain PFCAs. Air–water interfacial adsorption (AWIA) was the predominant source of retention (≥63%) for the long-chain PFCAs. Conversely, AWIA contributed less to retention than did solid-phase sorption for the short-chain PFCAs, with the former contributions ranging from 4% to 40%. Direct examination of the breakthrough-curve profiles as well as mathematical-modeling results demonstrated that transport of the two longest-chain PFCAs was influenced by nonlinear AWIA, whereas that of the shorter-chain PFCAs was not. This disparate behavior is consistent with the input concentration used for the transport experiments in comparison to the respective surface activities and critical reference concentrations of the different PFCAs. Quantitative-structure/property-relationship (QSPR) analysis was applied to characterize the influence of molecular size on air-water interfacial adsorption. The logs of the air-water interfacial adsorption coefficients ( K ia ) determined from the transport experiments are a monotonic function of molar volume, consistent with prior QSPR analyses of surface-tension measured values. The K ia values determined from the transport experiments are very similar to those measured from surface-tension data, indicating that the transport experiments produced robust measurements of AWIA.
研究领域:
环境科学
·
化学
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF CHROMATOGRAPHY A
·
2024
·
IF 3.8
Huan Liu,Siyuan Di,Yunkang Liu,Zihan Li,Pin Chen,Shukui Zhu
A novel magnetic mesoporous fluorinated metal-organic framework material (Fe 3 O 4 @MIP-206-F) has been synthesized specifically for application as an adsorbent for perfluoroalkyl carboxylic acids (PFCAs) extraction by magnetic solid-phase extraction (MSPE). The carefully designed Fe 3 O 4 @MIP-206-F material features an appropriate porosity, open metal sites of Zr, and functional groups (fluorine and amino) conducive to the adsorption process. The distinctive architecture of the material endows it with exceptional extraction capabilities for PFCAs. Adsorption mechanisms encompass acid-base interactions, hydrophobic interactions, F-F interactions, electrostatic interactions, and size complementarity. Optimization of key parameters has significantly improved the extraction efficiency of MSPE. When coupled with gas chromatography-mass spectrometry (GC–MS), MSPE offers rapid and highly sensitive analysis of PFCAs. The method demonstrates wide linear range (0.050–50 ng mL −1 ), low detection limits (0.0010–0.0019 ng mL −1 ), good recoveries (86.7 % to 111 %), and exceptional intra- and inter-day precision. This approach accurately quantifies PFCAs in lake water and groundwater samples, enabling precise assessment of environmental contamination levels and supporting targeted remediation efforts.
研究领域:
环境科学
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）