Perfluorooctane Sulfonate In Water Research Articles

Rapid Detection of ppt Concentration of Perfluorooctane Sulfonate in Water by Quartz Crystal Microbalance Loaded with MOF-808

Rapid Detection of ppt Concentration of Perfluorooctane Sulfonate in Water by Quartz Crystal Microbalance Loaded with MOF-808

Perfluorooctane sulfonate in water and sediment from the Yangtze Estuary and coastal waters: Occurrence, partitioning and diffusion behavior and risk assessment

As an emerging environmental contaminant, perfluorooctane sulfonate (PFOS) has attracted increasing attention. This study investigated the occurrence, partitioning and diffusion behavior, and risk assessment of PFOS in 19 water and sediment samples collected from the Yangtze Estuary and coastal waters in March 2022. The concentration of PFOS is 0.053–0.95 ng L−1 in water and 0.031–0.18 ng g−1 (dw) in sediments, demonstrating a transparent concentration gradient from inshore to offshore sites. The fugacity fraction model results showed that, except for a few sites, the diffusion trend of PFOS was from sediment into the water. Correlation and response coefficient (RC) analyses revealed a significant relationship between sediment organic carbon (TOC) and PFOS partitioning. According to the sediments-water partitioning coefficient Kd, in estuarine areas, seawater salinity tended to allocate PFOS to sediments. Ecological risk assessment findings revealed that PFOS posed a low to moderate risk in sediment rather than a problem in water.

Molecular dynamics simulation of the distribution of potassium perfluorooctanesulfonate in water

Molecular dynamics simulation of the distribution of potassium perfluorooctanesulfonate in water

Novel MOF-808 metal–organic framework as highly efficient adsorbent of perfluorooctane sulfonate in water

Perfluorooctane sulfonate (PFOS) is a highly persistent contaminant of emerging concern causing harmful effects to human and ecosystem health. In this study, a novel MOF-808 metal–organic framework (MOF) was prepared and evaluated for adsorptive removal of PFOS from aqueous solution. The MOF-808 had high specific surface area (SSA; 1610 m2/g) and was structurally stable in aqueous medium for 7 days under different pH conditions. The MOF-808 reached PFOS adsorption equilibrium within 30 min (at 500 mg/L initial PFOS) and attained the maximum adsorption capacity of 939 mg/g at pH 4.1 – 5.4 (with 50 – 500 mg/L initial PFOS). The PFOS adsorption capacity of MOF-808 was unaffected at pH 2 to 7, but gradually decreased at pH > 7. High SSA, favorable pore size and abundant active adsorption sites on MOF-808 triggered high PFOS adsorption onto the adsorbent. The PFOS adsorption process was endothermic and spontaneous in nature. Electrostatic interaction between the cationic central cluster ([Zr6O4(OH)4]12+) of MOF-808 and PFOS anion was identified as the key mechanism of PFOS adsorption onto MOF-808, as evident from the infrared spectroscopic investigation of the adsorbent. This study suggests that MOF-808 can be considered as a highly efficient adsorbent for PFOS removal from water and warrants future research to evaluate the application and performance of the material under wastewater conditions.

A regional numerical environmental multimedia modeling approach to assess spatial Eco-Environmental exposure risk of perfluorooctane sulfonate (PFOS) in the Pearl river basin.

This paper presents a novel numerical environmental multimedia modeling system (RNEMM) for assessing the environmental fate of emerging organic contaminants and their relative health risk at a regional scale. The RNEMM is developed based on an integrated numerical algorithm that comprises four sub-models: a river network simulation module, a gaseous phase simulation module, a mass balance based simulation module for soil compartment, and a food web analysis module. This RNEMM has been applied to simulate the spatial distribution of PFOS and assess the consequent health risks for a central water basin region of the Pearl River in China. The study region includes the urban areas of Guangzhou, Foshan, and Dongguan Cities with emission sources of PFOS, which was detected in local water, sediments, and air environment. The spatial concentration distributions of PFOS in water, sediment, air, soil, and various fish species are examined based on RNEMM and compared with the measured data. With a focus on water environment, it shows that the simulated results essentially agree well with measured concentrations. Comparing the simulated results and the measured data collected in 2013, the relative errors are mostly less than 40 % in the surface water and sediment zones for this regional scale field study. Whereas the relative error in the atmosphere zone is less than 5%. In addition, the health risk assessment for children and adults is conducted based on the RNEMM approach. The hazard quotient (HQ) values for the 95th percentile in most subareas of the study region are higher than 0.1, showing a low-risk level for the study period. The results indicate that the RNEMM is a useful modeling tool to manage the environmental and health risks associated with emerging contaminants on regional air, water, soil, and ecosystem at an adequate spatial-temporal resolution.

Fluorescence detection of perfluorooctane sulfonate in water employing a tetraphenylethylene-derived dual macrocycle BowtieCyclophane

Because the widely used perfluorooctane sulfonate (PFOS) is harmful to both environment and human health, it is of great significance and urgency to develop sensitive and selective sensors for the detection of trace PFOS in water. In this study, a tetraphenylethylene-derived macrocycle BowtieCyclophane has been developed as a fluorescent sensor based on aggregation-induced emission enhancement and fluorochromism. Sensitive detection of PFOS has been achieved with a limit of detection (LOD) of 47.3 ± 2.0 nmol/L (25.4 ± 1.1 µg/L) accompanied by visual fluorescence color changes.

Energy-efficient removal of PFOA and PFOS in water using electrocoagulation with an air-cathode

Electrocoagulation (EC) with a zinc anode demonstrated promising results to remove perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) from an aqueous solution. However, the energy requirement for EC is usually very high due to water electrolysis or aeration. This study aims to reduce energy consumption using an air-cathode in EC (ACEC) to supply oxygen electron acceptor without aeration for attenuating PFOA/PFOS in this new configuration. For the high PFOA concentration (0.25 mM), ACEC with 45 min of the reaction time exhibited an excellent PFOA removal (99.8 ± 0.3% removal) comparable to an EC with aeration (EC-aeration, 100% removal) while achieving much less energy consumption (0.14 kWh/m3). For the low PFOA concentration (0.1 μM), only 41.1 ± 11.6% was removed by the ACEC due to the low concentration gradient for adsorption. EC-aeration achieved higher PFOA removal (81.9 ± 15.1%) for the low PFOA concentration, possibly because air bubbles floated PFOA to the water surface, thereby concentrating PFOA. The PFOS removals in the ACEC and EC-aeration (76.4–88.5%) at the high concentration (0.25 mM) were lower than PFOA due tentatively to its micelle formation. However, PFOS was removed better than PFOA at the low concentration (0.1 μM) due to its higher hydrophobicity.

Adsorption and solid-phase photocatalytic degradation of perfluorooctane sulfonate in water using gallium-doped carbon-modified titanate nanotubes

Perfluorooctane sulfonate (PFOS) has drawn increasing attention due to its omnipresence and adverse health effects. We prepared a new adsorptive photocatalyst, Ga/[email protected], based on activated carbon and TiO2, and tested the adsorption and subsequent solid-phase photodegradation of PFOS. Ga/[email protected] showed faster adsorption kinetics and higher affinity for PFOS than the parent AC, and could degrade 75.0% and mineralize 66.2% of pre-sorbed PFOS within 4-h UV irradiation. The efficient PFOS photodegradation also regenerates Ga/[email protected], allowing for repeated uses without invoking chemical regenerants. The superior photoactivity is attributed to the oxygen vacancies, which not only suppressed recombination of the e−/h+ pairs, but also facilitated O2− generation. Both h+ and O2− played critical roles in the PFOS degradation, which starts with cleavage of the sulfonate group and converts it into PFOA that is then decarboxylated and defluorinated following the stepwise defluorination mechanism. Ga/[email protected] holds the potential for more cost-effective PFOS degradation.

CycloPure gets cash for water filtration

CycloPure, a start-up developing water filtration products, has raised $5 million to accelerate commercialization of its cyclodextrin polymer technology. The company, founded by Northwestern University chemistry professor Will Dichtel, says its porous, cross-linked polymer can adsorb micropollutants such as perfluorooctane sulfonate in water. The polymer combines β-cyclodextrin, derived from corn starch, and other monomers.

Occurrence, distribution and behavior of emerging persistent organic pollutants (POPs) in a Mediterranean wetland protected area

The analysis of perfluoroalkyl substances (PFASs) and organophosphate flame retardants (PFRs) in the different environmental compartments of a characteristic coastal wetland, the Albufera Natural Park (Valencia, Spain), is required for understanding the transport, accumulation and fate of these pollutants in an area under high anthropogenic pressure. Samples included 13 wastewater treatment plant influents, 13 effluents, 12 surface water, 19 sediment samples and 10 fish individuals from the Albufera Natural Park and the surrounding area. Tris(2-chloroisopropyl) phosphate (TCIPP) and perfluorooctane sulfonate (PFOS) were at the highest concentrations in water, 330.2 ng L−1 and 47.8 ng L−1, respectively. In fish and sediment PFOS was also the most detected while perfluorooctanoic acid (PFOA) was in all types of water. Higher levels of target compounds (mainly PFASs) in wastewater effluents compared to influent suggested both, formation from precursors during treatment and poor removal efficiency. Mean levels of PFOS in water and fish were higher than the environmental quality standards (EQS) established by the European Union Directive 2013/39/EU. The influence of the metropolitan area of Valencia and its surrounding industrial belt could explain the significantly higher levels reported in the northern part (influenced by the Turia River).

The presence of MWCNTs reduces developmental toxicity of PFOS in early life stage of zebrafish

Both carbon nanotubes (CNTs) and perfluorooctane sulfonate (PFOS) are used widely. There is considerable concern regarding their ecotoxicity. CNTs might interact with PFOS in water and result in different impacts compared with those after single exposures. To our knowledge, the developmental toxicity of PFOS in the presence of multi-walled carbon nanotubes (MWCNTs) in the early life stage of zebrafish (from 3 h post fertilization (hpf) to 96 hpf) was investigated for the first time in this study. The embryos and larvae were exposed to PFOS (0.2, 0.4, 0.8, and 1.6 mg/L), MWCNTs (50 mg/L), and a mixture of both. Compared with PFOS exposure, the adverse effects induced by PFOS on the hatching rate of zebrafish embryos and the heart rate and body length of zebrafish larvae were reduced in the presence of MWCNTs, and mortality and malformation were also alleviated. In addition, zebrafish larvae exposed to PFOS showed decreased activities of superoxide dismutase, catalase, and glutathione peroxidase, as well as decreased levels of reactive oxygen species and malondialdehyde, in the presence of MWCNTs, indicating that oxidative stress and lipid peroxidation was relieved. Thus, the presence of MWCNTs reduces the developmental toxicity of PFOS in the early life stage of zebrafish.

Toxicokinetics of perfluorooctane sulfonate in rainbow trout (Oncorhynchus mykiss).

Rainbow trout (Oncorhynchus mykiss) confined to respirometer-metabolism chambers were dosed with perfluorooctane sulfonate (PFOS) by intra-arterial injection and sampled to obtain concentration time-course data for plasma and either urine or expired water. The data were then analyzed using a 2-compartment clearance-volume model. Renal and branchial clearance rates (mL/d/kg) determined for all experiments averaged 19% and 81% of total clearance, respectively. Expressed as mean values for all experiments, the steady-state volume of distribution was 277 mL/kg and the terminal half-life was 86.8 d. Additional animals were exposed to PFOS in water, resulting in an average calculated branchial uptake efficiency of 0.36%. The renal clearance rate determined in the present study is approximately 75 times lower than that determined in earlier studies with perfluorooctanoate (PFOA). Previously, it was suggested that PFOA is a substrate for membrane transporters in the trout kidney. The present study suggests that glomerular filtration may be sufficient to explain the observed renal clearance rate for PFOS, although a role for membrane transporters cannot be ruled out. These findings demonstrate that models developed to predict the bioaccumulation of perfluoroalkyl acids by fish must account for differences in renal clearance of individual compounds.

Determination and partitioning behavior of perfluoroalkyl carboxylic acids and perfluorooctanesulfonate in water and sediment from Dianchi Lake, China

Perfluorinated compounds (PFCs) have received much attention on their distribution in various matrices including water bodies, precipitations, sediment and biota in different areas globally, however, little attention has been paid to their occurrence and distribution in urban lakes. In this study, water and sediment samples collected from 26 sites in Dianchi Lake, a plateau urban lake in the southwestern part of China were analyzed via high performance liquid chromatography–tandem mass spectrometry (HPLC–MS/MS) for ten analytes involving nine perfluoroalkyl carboxylic acids (PFOAs) and perfluorooctanesulfonate (PFOS). Total levels of PFCs were 30.98±32.19ngL−1 in water and 0.95±0.63ngg−1 in sediment. In water samples PFOA was the dominant PFC contaminant, with concentrations ranging from 3.41 to 35.44ngL−1, while in sediments PFOS was the main PFC contaminant at levels from 0.07–0.83ngg−1 dry weight. Field-based sediment water distribution coefficients (KD) were calculated and corrected for organic carbon content (Koc), which reduced variability among samples. The logKoc ranged from 2.54 to 3.57 for C8–C12 perfluorinated carboxylic acids, increasing by 0.1–0.4 log units with each additional CF2 moiety. The logKoc of PFOS was 3.35±0.32. Magnitudes and trends in logKD or logKoc appeared to agree well with previously published laboratory data. Results showed that different PFC composition profiles were observed for samples from the lake water and sediments, indicating the presence of dissimilar characteristics of the PFCs compounds, which is important for PFC fate modeling and risk assessment.

Oxidative decomposition of perfluorooctanesulfonate in water by permanganate

Experiments were conducted to examine the oxidative decomposition of perfluorooctanesulfonate (PFOS), a widely distributed and highly resistant emerging organic pollutant, by permanganate in aqueous solutions. At 65°C and pH 4.2, 46.8% of the PFOS was decomposed by permanganate, with a F– yield of 5.3% and a SO42- yield of 36.9%. The effects of temperature, initial permanganate concentration, and pH on PFOS decomposition efficiency were systematically investigated with batch experiments. Increasing the temperature and initial permanganate concentration effectively accelerated the rate of PFOS decomposition. However, increased pH decreased the PFOS decomposition rate, therefore indicating that a more acidic solution favors the decomposition of PFOS by permanganate. Moreover, the autocatalysis effect was found to accelerate the rate of PFOS decomposition by the in situ formed MnO2 from the reduction of permanganate and, thus, the addition of MnO2 to the reaction solution also increased the decomposition rate. Under acidic conditions, the addition of organic acids can enhance their complexation with Mn(V) and Mn(VI). Therefore, the duration of the Mn(VII) reduction intermediates, which are highly active and easily disproportionated and autodecomposed, can be further prolonged to facilitate the oxidative decomposition of PFOS.

Perfluorinated compounds in surface waters from Northern China: Comparison to level of industrialization

Inclusion of Perfluorooctane Sulfonate (PFOS) in the Stockholm Convention because of its exemptions, has resulted in increased annual production of PFOS-containing chemicals in China to accommodate domestic and overseas demands. Accordingly, concern about environmental contamination with perfluorinated compounds (PFCs), such as PFOS, has arisen. However, little information is available on the status and trends in the distribution, sources or risk of PFCs in aquatic environments of China. In the present study, forty two surface water samples collected from five regions with different levels of industrialization were monitored for concentrations of PFCs by use of solid phase extraction and LC/MS/MS. Mean concentrations (maximum concentration) of PFOA and PFOS, which were the dominant PFCs, were 1.2 (2.3) and 0.16 (0.52)ng/l for Guanting, 1.2 (1.8) and 0.32 (1.1)ng/l for Hohhot, 2.7 (15) and 0.93 (5.7)ng/l for Shanxi, 6.8 (12) and 2.6 (11)ng/l for Tianjin, 27 (82) and 4.7 (31)ng/l for Liaoning, respectively. The greatest concentrations of PFCs (121ng/l), PFOA (82ng/l) and PFOS (31ng/l) were observed in Liaoning, which might originate from tributaries of the Liaohe River, the most polluted watershed in Northeast China. While, concentrations of PFCs in the Guanting and Hohhot regions were 3 to 20 fold less than those from Tianjin and Liaoning. This result is consistent with little contribution of PFCs being released from agricultural and non-industrial activities. The magnitudes of mass flow for PFOA and PFOS in decreasing order were: Guanting<Hohhot<Tianjin<Liaoning<Shanxi and Guanting<Hohhot<Shanxi<Tianjin<Liaoning. The larger mass flows of PFOS were accompanied by relatively larger magnitudes of PFOA. Concentrations of both PFOA and PFOS in waters from all regions were less than suggested allowable concentrations. However, the relatively greater concentrations of PFCs in Tianjin and Liaoning suggest that further studies characterizing their sources and potential risk to both humans and wildlife are needed.

Fast screening of perfluorooctane sulfonate in water using vortex-assisted liquid–liquid microextraction coupled to liquid chromatography–mass spectrometry

Fast screening of trace amounts of the perfluorooctane sulfonate anion (PFOS) in water samples was performed following a simple, fast and efficient sample preparation procedure based on vortex-assisted liquid–liquid microextraction (VALLME) prior to liquid chromatography–mass spectrometry. VALLME initially uses vortex agitation, a mild emulsification procedure to disperse microvolumes of octanol, a low density extractant solvent, in the aqueous sample. Microextraction under equilibrium conditions is thus achieved within few minutes. Subsequently, centrifugation separates the two phases and restores the initial microdrop shape of the octanol acceptor phase, which can be collected and used for liquid chromatography–single quadrupole mass spectrometry analysis. Several experimental parameters were controlled and the optimum conditions found were: 50 μL of octanol as the extractant phase; 20 mL aqueous donor samples (pH = 2); a 2 min vortex extraction time with the vortex agitator set at a 2500 rpm rotational speed; no ionic strength adjustment. Centrifugation for 2 min at 3500 rpm yielded separation of the two phases throughout this study. Enhanced extraction efficiencies were observed at low pH which was likely due to enhanced electrostatic interaction between the negatively PFOS molecules and the positively charged octanol/water interface. The effect of pH was reduced in the presence of sodium chloride, likely due to electrical double layer compression. The linear response range for PFOS was from 5 to 500 ng L −1 (coefficient of determination, r 2, 0.997) and the relative standard deviation for aqueous solutions containing 10 and 500 ng L −1 PFOS were 7.4% and 6.5%, respectively. The limit of detection was 1.6 ng L −1 with an enrichment factor of approximately 250. Analysis of spiked tap, river and well water samples revealed that matrix did not affect extraction.

A comparative study of adsorption of perfluorooctane sulfonate (PFOS) onto granular activated carbon, ion-exchange polymers and non-ion-exchange polymers

Perfluorooctane sulfonate (PFOS) is the latest chemical categorized as persistent organic pollutants (POPs). PFOS appears in the environmental water and tap water in ng L −1 level. The process of adsorption has been identified as an effective technique to eliminate PFOS in water. Three non-ion-exchange polymers (DowV493, DowL493 and AmbXAD4), two ion-exchange polymers (DowMarathonA and AmbIRA400) and one granular activated carbon (GAC) (Filtersorb400) were tested with regard to their sorption kinetics and isotherms at low PFOS concentrations (100–1000 ng L −1 equilibrium concentrations). The sorption capacities at 1 μg L −1 equilibrium concentration decreased in the following order: Ion-exchange polymers > non-ion-exchange polymers > GAC, but at further low equilibrium concentration (100 ng L −1) non-ion-exchange polymers showed higher adsorption capacity than other adsorbents. In the case of sorption kinetics, GAC and ion-exchange polymers reached the equilibrium concentration within 4 h and AmbXAD4 within 10 h. DowV493 and DowL493 took more than 80 h to reach equilibrium concentration. AmbIRA400 was identified as the best filter material to eliminate PFOS at equilibrium concentration >1000 ng L −1. Considering both adsorption isotherms and adsorption kinetics, AmbXAD4 and DowMarathonA were recommended to eliminate PFOS at ng L −1 equilibrium concentration.

タイ王国湖沼および湾岸における有機フッ素系界面活性剤の現状

Perfluorooctanoic acid (PFOA) and Perfluorooctane sulfonate (PFOS) as persistence organic pollutants (POPs) have been detected in environmental waters around the world. However, only few information on PFOA and PFOS in the Thai environment has been obtained. In order to clarify the pollutions of PFOA and PFOS in waters of lakes and seaside areas in Thailand, we analyzed PFOS and PFOA with SPE-LC/MS in water samples in Kasetsert University in Bangkok, Thailand. However, commercial methanol and RO water for LC/MS analysis purchased from chemical companies in Bangkok were contaminated with PFOS and PFOA before use. The contaminants in the solvent and the commercial pure water were removed using a mix-mode anion exchange solid-phase extraction cartridge (OASIS MAX, Waters). PFOS and PFOA were detected from all samples at the ranges between 0.8 and 61.7 ng/L and between 10.0 and 29.0 ng/L, respectively. It should be noted that the molar ratios of PFOS and PFOA in the East-side and the West-side of the Thai Gulf were different. The finding suggests that the pollutants in the both sides might be drained from different sources.

Photodegradation of Perfluorooctane Sulfonate by UV Irradiation in Water and Alkaline 2-Propanol

Perfluorooctane sulfonate (PFOS) is the environmentally concerned compound because of its persistence and bioaccumulative properties. Since photodegradation of PFOS is not yet experimentally confirmed, photodegradation study of PFOS in water and alkaline 2-propanol solution was conducted. Aqueous and alkaline 2-propanol solution of PFOS (40 microM) was irradiated with a low-pressure mercury lamp (254 nm, 32 W) by internal irradiation for 10 d, and then PFOS, fluoride and sulfate ions, and the other degradation products were analyzed. Photodegradation of PFOS was confirmed in both media. PFOS was degraded by 8% after 1 day and by 68% after 10 days irradiation compared to the initial concentration in water. In alkaline 2-propanol, 76 and 92% of PFOS was degraded after 1 and 10 days irradiation, respectively. Photodegradation of PFOS in alkaline 2-propanol was much faster and effective than in water, as the photodegradation rate constants were 0.93 days(-1) in alkaline 2-propanol and 0.13 days(-1) in water, respectively. Formation of fluoride and sulfate was also confirmed by ion chromatography and X-ray diffraction analysis. From observation of the degradation products, two major degradation pathways of PFOS were considered: via C8HF17 and C8F17OH, respectively, resulting in short-chain fluorinated compounds such as C7HF15 and C7F15OH by stepwise removal of CF2. Formation of short-chain fluorocarbons such as CF4, C2F6, and C3F8 were also confirmed. This is the first study to confirm photodegradation of PFOS in water and alkaline 2-propanol.

Efficient Decomposition of Environmentally Persistent Perfluorooctanesulfonate and Related Fluorochemicals Using Zerovalent Iron in Subcritical Water

Decomposition of perfluorooctanesulfonate (PFOS) and related chemicals in subcritical water was investigated. Although PFOS demonstrated little reactivity in pure subcritical water, addition of zerovalent metals to the reaction system enhanced the PFOS decomposition to form F-ions, with an increasing order of activity of no metal approximately equal Al < Cu < Zn << Fe. Use of iron led to the most efficient PFOS decomposition: When iron powder was added to an aqueous solution of PFOS (93-372 microM) and the mixture was heated at 350 degrees C for 6 h, PFOS concentration in the reaction solution fell below 2.2 microM (detection limit of HPLC with conductometric detection), with formation of F-ions with yields [i.e., (moles of F- formed)/(moles of fluorine content in initial PFOS) x 100] of 46.2-51.4% and without any formation of perfluorocarboxylic acids. A small amount of CHF3 was detected in the gas phase with a yield [i.e., (moles of CHF3)/(moles of carbon content in initial PFOS) x 100] of 0.7%, after the reaction of PFOS (372 microM) with iron at 350 degree C for 6 h. Spectroscopic measurements indicated that PFOS in water markedly adsorbed on the iron surface even at room temperature, and the adsorbed fluorinated species on the iron surface decomposed with rising temperature, with prominent release of F- ions to the solution phase above 250 degrees C. This method was also effective in decomposing other perfluoroalkylsulfonates bearing shorter chain (C2-C6) perfluoroalkyl groups and was successfully applied to the decomposition of PFOS contained in an antireflective coating agent used in semiconductor manufacturing.