A review of sample collection and analytical methods for detecting per- and polyfluoroalkyl substances in indoor and outdoor air.

Per- and polyfluoroalkyl substances (PFAS) are a unique class of chemicals synthesized to aid in industrial processes, fire-fighting products, and to benefit consumer products such as clothing, cosmetics, textiles, carpets, and coatings. The widespread use of PFAS and their strong carbon-fluorine bonds has led to their ubiquitous presence throughout the world. Airborne transport of PFAS throughout the atmosphere has also contributed to environmental pollution.

Mechanochemical destruction of per- and polyfluoroalkyl substances in aqueous film-forming foams and contaminated soil.

Per- and polyfluoroalkyl substances (PFASs) are a class of synthetic chemicals of concern that exhibit extreme persistence within the environment and possess physicochemical properties that are resistant to targeted degradation. Comprising substantial concentrations of PFASs, aqueous film-forming foams (AFFFs) present a major exposure pathway to the environment having been applied to land at firefighting-training sites globally for decades. This has led to significant contamination of environmental media.

Pilot-Scale Thermal Destruction of Per- and Polyfluoroalkyl Substances in a Legacy Aqueous Film Forming Foam.

The destruction of per- and polyfluoroalkyl substances (PFAS) is critical to ensure effective remediation of PFAS contaminated matrices. The destruction of hazardous chemicals within incinerators and other thermal treatment processes has historically been determined by calculating the destruction efficiency (DE) or the destruction and removal efficiency (DRE). While high DEs, >99.

Low temperature destruction of gas-phase per- and polyfluoroalkyl substances using an alumina-based catalyst.

Per- and polyfluoroalkyl substances (PFAS) pose a major health and environmental problem. Methods are needed to ensure that PFAS are not released into the environment during their use or disposal. Alumina-based catalysts have been used for the abatement of small perfluorocarbons, e.

Characterization of PFAS air emissions from thermal application of fluoropolymer dispersions on fabrics.

During thermal processes utilized in affixing fluoropolymer coatings dispersion to fibers and fabrics, coating components are vaporized. It is suspected that per- and polyfluoroalkyl substances (PFAS) from the dispersions may undergo chemical transformations at the temperatures used, leading to additional emitted PFAS thermal byproducts. It is important to characterize these emissions to support evaluation of the resulting environmental and health impacts.

Combustion of C and C PFAS: Kinetic modeling and experiments.

A combustion model, originally developed to simulate the destruction of chemical warfare agents, was modified to include C-C fluorinated organic reactions and kinetics compiled by the National Institute of Standards and Technology (NIST). A simplified plug flow reactor version of this model was used to predict the destruction efficiency (DE) and formation of products of incomplete combustion (PICs) for three C and C per- and poly-fluorinated alkyl substances (PFAS) (CF, CHF, and CF) and compare predicted values to Fourier Transform Infrared spectroscopy (FTIR)-based measurements made from a pilot-scale EPA research combustor (40-64 kW, natural gas-fired, 20% excess air). PFAS were introduced through the flame, and at post-flame locations along a time-temperature profile allowing for simulation of direct flame and non-flame injection, and examination of the sensitivity of PFAS destruction on temperature and free radical flame chemistry.

Developing innovative treatment technologies for PFAS-containing wastes.

The release of persistent per- and polyfluoroalkyl substances (PFAS) into the environment is a major concern for the United States Environmental Protection Agency (U.S. EPA).

Supercritical Water Oxidation as an Innovative Technology for PFAS Destruction.

Water above 374 °C and 22.1 MPa, becomes supercritical, a special state where organic solubility increases and oxidation processes are accelerated. Supercritical water oxidation (SCWO) has been previously shown to destroy hazardous substances such as halogenated compounds.

Low Temperature Thermal Treatment of Gas-Phase Fluorotelomer Alcohols by Calcium Oxide.

Given the extent to which per- and polyfluoroalkyl substances (PFAS) are used in commercial and industrial applications, the need to evaluate treatment options that reduce environmental emissions and human and ecological exposures of PFAS is becoming more necessary. One specific chemical class of PFAS, fluorotelomer alcohols (FTOHs), have vapor pressures such that a significant fraction is expected to be present in the gas-phase even at ambient temperatures. FTOHs are used in a variety of PFAS applications, including synthesis and material coatings.

An End-of-Life Care Educational Series to Improve Staff Knowledge and Comfort Levels.

Nursing staff play a key role in enhancing a patient's quality of life during end of life; however, they perceive lack of knowledge to be the largest barrier in providing quality end-of-life (EOL) care. Literature suggests that implementation of palliative and EOL care education can improve nursing EOL care practices. In order to address the gap in nursing knowledge and comfort, a quasi-experimental study was conducted; this study included the implementation of a multimodal EOL care educational series on an inpatient pediatric hematology oncology floor over 6 months.

A crosslinked, low pH-stable, mixed-mode cation-exchange like stationary phase made using the thiol-yne click reaction.

Mixed-mode cation-exchange stationary phases are useful for the separation of mixtures containing hydrophobic, acidic, and basic molecules. To ensure that weak organic bases are protonated and carboxylic acids are neutral low pH mobile phases are required. Mixed-mode stationary phases that are stable at pH < 3 are needed.

A pH-stable, crosslinked stationary phase based on the thiol-yne reaction.

Stationary phases that can withstand extremes of pH and temperature are needed to allow a single column to accommodate a wider set of solutes and separation criteria. We used a simple multi-step process using the thiol-yne reaction following the modification of the silica surface with a thiol-containing silane. The monomers 1,4-diethynylbenzene (DEB) and 1,6-hexanedithiol were used to create a crosslinked thiol-yne (CTY) stationary phase along the surface of the thiol functionalized silica.

A liquid chromatographic charge transfer stationary phase based on the thiol-yne reaction.

In the process of developing a pH-stable, highly crosslinked stationary phase using the thiol-yne reaction, a new charge transfer stationary phase was discovered. The first step in the preparation of the crosslinked phase is to attach 1,4-diethynylbenzene (DEB) to thiol functionalized silica particles using the thiol-yne reaction. Upon preparation of that phase, we noticed that the color of the particles was different when the modified particles were wet with aromatic solvents in comparison to wetting with nonaromatic or aqueous solvents.

Evaluation of solid particle number and black carbon for very low particulate matter emissions standards in light-duty vehicles.

Unlabelled: To reliably measure at the low particulate matter (PM) levels needed to meet California's Low Emission Vehicle (LEV III) 3- and 1-mg/mile particulate matter (PM) standards, various approaches other than gravimetric measurement have been suggested for testing purposes. In this work, a feasibility study of solid particle number (SPN, d50 = 23 nm) and black carbon (BC) as alternatives to gravimetric PM mass was conducted, based on the relationship of these two metrics to gravimetric PM mass, as well as the variability of each of these metrics. More than 150 Federal Test Procedure (FTP-75) or Supplemental Federal Test Procedure (US06) tests were conducted on 46 light-duty vehicles, including port-fuel-injected and direct-injected gasoline vehicles, as well as several light-duty diesel vehicles equipped with diesel particle filters (LDD/DPF).