Health & Environmental Research Online (HERO)


Per- and Polyfluoroalkyl Substances (PFAS)


1,557 References Were Found:

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Electrochemical mineralization of perfluorooctane sulfonate by novel F and Sb co-doped Ti/SnO2 electrode containing Sn-Sb interlayer

Authors: Yang, Bo; Wang, J; Jiang, C; Li, J; Yu, G; Deng, S; Lu, S; Zhang, P; Zhu, C; Zhuo, Q (2017) HERO ID: 3981856

[Less] The F and Sb co-doped Ti/SnO2 electrode containing Sn-Sb interlayer was innovatively synthesized for . . . [More] The F and Sb co-doped Ti/SnO2 electrode containing Sn-Sb interlayer was innovatively synthesized for electro-oxidation (EO) removal of perfluorooctane sulfonate (PFOS) in water. Stronger oxidation capability and remarkably longer lifetime were performed for Ti/Sn-Sb/SnO2-F-Sb electrode than these similar electrodes in this study without Sn-Sb interlayer and F/Sb doping, which could removed more than 99% of PFOS (C-o = 100 mg L-1) after 120-min electrolysis. The attribute of Ti/Sn-Sb/SnO2-F-Sb anode and its EO mechanism-were surveyed by XRD, XPS, SEM, and LSV. F and Sb co-doping could improve the stability and EO capability of the electrode, which resulted from that the smooth surface was formed conveniently to produce physically adsorbed hydroxyl radical and lead to relatively high OEP. The operating parameters of EO process were also investigated including current density, pH value, and stirring speed, which revealed the effect of these parameters on PFOS decomposition. Additionally, the mineralization parameters, TOC and F- concentration, as well as short-chain perfluorocarboxylic acids were analyzed in solution during the electrolysis. Consequently, the EO pathway of PFOS was proposed through the detection of intermediates. These results manifest that Ti/Sn-Sb/SnO2-F-Sb anode is prospective to effectively decompose PFOS in wastewater. (C) 2017 Elsevier B.V. All rights reserved.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Role of calcium ions on the removal of haloacetic acids from swimming pool water by nanofiltration: mechanisms and implications

Authors: Yang, L; Zhou, J; She, Q; Wan, MP; Wang, R; Chang, VW; Tang, CY (2017) HERO ID: 3981896

[Less] We investigated the removal of haloacetic acids (HAAs) from swimming pool waters (SPWs) by two nanofiltration . . . [More] We investigated the removal of haloacetic acids (HAAs) from swimming pool waters (SPWs) by two nanofiltration membranes NF270 and NF90. The strong matrix effect (particularly by Ca(2+)) on membrane rejection prompts us to systematically investigate the mechanistic role of Ca(2+) in HAA rejection. At typical SPW pH of 7.5, NF90 maintained consistently high rejection of HAAs (>95%) with little influence by Ca(2+), thanks to the dominance of size exclusion effect for this tight membrane (pore radius ∼ 0.31 nm). In contrast, the rejections of both inorganic ions (e.g., Na(+) and Cl(-)) and HAA anions were decreased at higher Ca(2+) concentration for NF270 (pore radius ∼ 0.40 nm). Further tests show that the rejection of neutral hydrophilic molecular probes and the membrane pore size were not affected by Ca(2+). Although Ca(2+) is unable to form strong complex with HAAs, we observed the binding of Ca(2+) to NF270 together with a reduction in its surface charge. Therefore, the formation of membrane-Ca(2+) complex, which weakens charge interaction effect, was responsible for the reduced HAA rejection. The current study reveals important mechanistic insights of the matrix effect on trace contaminant rejection, which is critical for a better understanding of their fate and removal in membrane-based treatment.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Components and parameters of solid/surfactant layer surface tension

Authors: Zdziennicka, A; Szymczyk, K; Krawczyk, J; Janczuk, B (2017) HERO ID: 3981782

[Less] Measurements of the contact angle for water, formamide and diiodomethane on the layers of R-95 Rhamnolipid, . . . [More] Measurements of the contact angle for water, formamide and diiodomethane on the layers of R-95 Rhamnolipid, surfactin, n-octyl-beta-D-glucopyranoside, n-dodecyl-beta-D-glucopyranoside, n-dodecyl-beta-D-maltoside, sucrose monodecanoate, sucrose monododecanoate, Tween 20, Tween 60 and Tween 80 as well as rhamnose, sucrose and poly(ethylene glycol) 8000 deposited on polytetrafluoroethylene, polyethylene, polymethyl methacrylate, polyamide and quartz were made. On the basis of the obtained results the changes of surface properties of the studied solids under the influence of the surfactants as well as rhamnose, sucrose and poly(ethylene glycol) 8000 layer were considered using different theoretical methods From these considerations it was deduced that hydrophilic and hydrophobic balance of a given solid surface covered by the surfactant layer changes as a function of the layer thickness and kind of surfactant. However, surface properties of the thick layer of a given surfactant does not depend on the kind of solids. These properties for biosurfactants are comparable to that of rhamnosa, sugar surfactants to sucrose and Tween's to poly(ethylene glycol) 8000. (C) 2017 Elsevier B.V. All rights reserved.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

N-doped graphene quantum dots as a novel highly-efficient matrix for the analysis of perfluoroalkyl sulfonates and other small molecules by MALDI-TOF MS

Authors: Rao, Z; Geng, F; Zhou, Y; Cao, D; Kang, Y (2017) HERO ID: 3981823

[Less] N-doped graphene quantum dots (N-GQDs) were synthesized by a facile, rapid method based on a time-efficient . . . [More] N-doped graphene quantum dots (N-GQDs) were synthesized by a facile, rapid method based on a time-efficient bottom-up strategy. In addition, solid-phase extraction (SPE) was, for the first time, applied to the purification of N-GQDs, which was very time-efficient compared to the traditional dialysis method and facilitated the removal of salts and the obtention of N-GQDs with homogeneous size. The as-prepared N-GQDs, with good solubility in both organic solvents and water, were successfully employed as a novel matrix for the analysis of perfluoroalkyl sulfonates (PFSs) and other small molecules by MALDI-TOF MS. Compared with conventional matrices, N-GQDs displayed a superior efficiency, less background interferences, high sensitivity and good repeatability. The presence of polymorphous nitrogen species in GQDs and the p-conjugated structure contributed to an enhanced desorption/ionization efficiency. The homogeneity of the material provided a good repeatability. Furthermore, quantitative detection of perfluorooctane sulfonate (PFOS) in environmental samples was successfully determined by MALDI-TOF MS using N-GQDs; this suggests that N-GQDs have a potential to play an important role in the rapid, sensitive and precise analysis of trace levels of organic pollutants, such as PFSs. Thus, it is of great interest to broaden this method to apply it to the analysis of other small-molecular weight organic pollutants in the future.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Efficient photoreductive decomposition of N-nitrosodimethylamine by UV/iodide process

Authors: Sun, Z; Zhang, C; Zhao, X; Chen, J; Zhou, Q (2017) HERO ID: 3849043

[Less] N-nitrosodimethylamine (NDMA) has aroused extensive concern as a disinfection byproduct due to its high . . . [More] N-nitrosodimethylamine (NDMA) has aroused extensive concern as a disinfection byproduct due to its high toxicity and elevated concentration levels in water sources. This study investigates the photoreductive decomposition of NDMA by UV/iodide process. The results showed that this process is an effective strategy for the treatment of NDMA with 99.2% NDMA removed within 10min. The depletion of NDMA by UV/iodide process obeyed pseudo-first-order kinetics with a rate constant (k1) of 0.60±0.03min(-1). Hydrated electrons (eaq(-)) generated by the UV irradiation of iodide were proven to play a critical role. Dimethylamine (DMA) and nitrite (NO2(-)) were formed as the main intermediate products, which completely converted to formate (HCOO(-)), ammonium (NH4(+)) and nitrogen (N2). Therefore, not only the high efficiencies in NDMA destruction, but the elimination of toxic intermediates make UV/iodide process advantageous. A photoreduction mechanism was proposed: NDMA initially absorbed photons to a photoexcited state, and underwent a cleavage of NNO bond under the attack of eaq(-). The solution pH had little impact on NDMA removal. However, alkaline conditions were more favorable for the elimination of DMA and NO2(-), thus effectively reducing the secondary pollution.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Role of small molecular weight organic acids with different chemical structures as electron donors in the photocatalytic degradation of ronidazole: Synergistic performance and mechanism

Authors: Sun, Lei; Chen, D; Wan, S; Yu, Z; Li, M (2017) HERO ID: 3981767

[Less] The role of organic acids with different numbers of carboxyl and hydroxyl groups as electron donors . . . [More] The role of organic acids with different numbers of carboxyl and hydroxyl groups as electron donors in the photocatalytic degradation of ronidazole was demonstrated. The strength of the synergetic effect between photocatalysis and organic acids was related to the structure of the organic acid and followed the order of oxalic acid > citric acid approximate to malic acid > tartaric acid > lactic acid. Organic acids with hydroxyl groups are more important in the production of a synergetic effect than formic, malonic, and succinic acids without a hydroxyl group. The removal efficiency and first-order kinetic constant increased from 84.8% to 97.1% and 0.0314 min (1) to 0.0941 min (1), respectively, at 0.5 mmol L (1) oxalic acid, 0.1 mmol L (1) ronidazole concentration, and 0.5 g L (1) TiO2. The synergistic mechanism is that the organic acid reacts with photo-generated holes to prohibit the recombination of photo-generated electrons and holes as well as form strong reduction potential CO2 center dot radicals based on the results of scavenging experiments. The intermediates in pure photocatalysis and the photocatalytic-oxalic acid system were detected. The possible transformation pathways of ronidazole in the presence of oxalic acid were pro-posed, and such degradation is mainly a reduction process initiated by CO2 center dot and e . (C) 2017 Elsevier B.V. All rights reserved.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Hydrated electron (e(aq)(-)) generation from p-benzoquinone/UV: Combined experimental and theoretical study

Authors: Gu, Jia; Yang, L; Ma, Jun; Jiang, Jin; Yang, J; Zhang, J; Chi, H; Song, Y; Sun, S; Tian, WeiQ (2017) HERO ID: 3981817

[Less] A p-benzoquinone (p-BQ)/UV process to induce hydrated electron (e(aq)(-)) generation was predicted by . . . [More] A p-benzoquinone (p-BQ)/UV process to induce hydrated electron (e(aq)(-)) generation was predicted by quantum chemical calculations and validated by experiment in this work. Theoretically, the photolysis of p-BQ under UV irradiation at 253.7 nm could induce water to generate e(aq)(-) with a molar ratio of 1:2 via the direct triplet mechanism, in which 1,4-addition reaction of the first triplet state of p-BQ with water was the key step. Experimentally, monochloroacetic acid (MCAA) (the probe of e(aq)(-)) was used to detect e(aq)(-) generated in the p-BQIUV process. The generation efficiency showed a positive linear dependence on the p-BQ concentration, which illustrated the crucial role of p-BQ on the generation of e(aq)(-). During the photolysis, p-hydroquinone was the primary intermediate for the generation of e(aq)(-). Kinetically, the energy barriers of the e(aq)(-) generation from p-HOC6H4OH, p-HOC6H4O- and p--OO6H4O- were 100.8 kcal mol(-1), 46.5 kcal mol(-1) and 5.6 kcal mol(-1), respectively. Both the experimental and theoretical results show that the generation of e(aq)(-) was much more efficient from the anions than that from pHOC(6)H(4)OH. The findings in the present study may help to understand the mechanism of e(aq)(-) generation from natural organic matters (NOM), since quinone-like groups are usually contained in NOM. (C) 2017 Elsevier B.V. All rights reserved.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Selective separation of oil and water with special wettability mesh membranes

Authors: Liu, D; Yu, Y; Chen, Xin; Zheng, Y (2017) HERO ID: 3981861

[Less] Due to the different interfacial effects of oil and water, utilizing the specialwettability of solid . . . [More] Due to the different interfacial effects of oil and water, utilizing the specialwettability of solid surfaces to design an oil and water separation process has been demonstrated to be an effective approach for oil/water separation. In this report, a simple process has been developed to fabricate special surface wettability mesh membranes. The carbon nanoparticles with diameters of 10 nm were first coated onto the surface of steel wires based on a candle soot coating process. These templates of carbon nanoparticles were then coated with a more stable layer of silica (SiO2) particles via a facile chemical vapor deposition route. After being modified by two separate methods, a superhydrophobic/superoleophilic membrane was obtained by the use of 1H, 1H, 2H, 2H-perfluorooctyltrichlorosilane (PFOTS) and a oleophobic/superhydrophilic membrane was obtained by using poly(diallyldimethylammonium-perfluorooctanoate) (PDDA-PFO). Separation experiments show that these superhydrophobic/superoleophilic or oleophobic/superhydrophilic mesh membranes can be used to selectively separate oil/water with a high flux of more than 930 L m(-2) h(-1) and a collecting efficiency of over 97%. Furthermore, the repetitions of the separation experiments demonstrate that these superhydrophobic/superoleophilic or oleophobic/superhydrophilic mesh membranes are durable, stable and reusable, making them encouraging candidates for practical oil-polluted water treatment.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Matrix-assisted diffusion-ordered NMR spectroscopy with an invisible, tuneable matrix

Authors: Hernandez-Cid, A; Piekarska, M; Adams, RW; Nilsson, M; Evans, R; Morris, GA (2017) HERO ID: 3981878

[Less] Mixtures of species of similar sizes can be analysed with H-1 NMR using diffusion-ordered spectroscopy . . . [More] Mixtures of species of similar sizes can be analysed with H-1 NMR using diffusion-ordered spectroscopy (DOSY), by adding a co-solute with which different analytes interact to different extents ("matrix-assisted DOSY"). A matrix containing aqueous perfluorooctanoate micelles has the dual advantages of invisibility to H-1 NMR, and interactions tuneable by adjusting the pH.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Electrochemical Detection of Thioether-Based Fluorosurfactants in Aqueous Film-Forming Foam (AFFF)

Authors: Fanga, C; Megharaj, M; Naidu, R (2017) HERO ID: 3981874

[Less] Using cyclic voltammetry (CV) and impedance (IMP), we report a simple approach to detect new fluorosurfactant . . . [More] Using cyclic voltammetry (CV) and impedance (IMP), we report a simple approach to detect new fluorosurfactant ingredient formulated in aqueous film-forming foam (AFFF), specifically the thioether-based one. First, we employ ion chromatography (IC) to identify all possible elements with the help of chemical oxidation and infrared spectrum (IR) to identify all possible functional groups. We thus propose a possible thioether-based molecular structure of fluorosurfactant formulated in AFFF. By studying the self-assembled monolayer (SAM) formed on gold (Au) surface via thio-Au bond, we establish a relationship between the SAM density and the amount of the thioether-based fluorosurfactant for the AFFF detection. Solid phase extraction (SPE) and nanoporous Au electrode are employed to enhance the sensitivity. Consequently, a detection limit of 10 ppb (v/v) has been achieved for AFFF-spiked tap water sample.