Perfluoroalkyl chemical adsorption by granular activated carbon: Assessment of particle size impact on equilibrium parameters and associated rapid small-scale column test scaling assumptions.

Single-solute batch kinetic and isotherm experiments were conducted in Type 1 (18.2 MΩ·cm resistivity) water supplemented with 10 mM carbonate buffer (pH 7.75, 25 °C) for nine drinking water relevant perfluoroalkyl chemicals and three bituminous-coal based granular activated carbons (GACs).

Role of grinding method on granular activated carbon characteristics.

A coconut shell (AC1230CX) and a bituminous coal based (F400) granular activated carbon (GAC) were ground with mortar and pestle (MP), a blender, and a bench-scale ball milling unit (BMU). Blender was the most time-efficient for particle size reduction. Four size fractions ranging from 20 × 40 to 200 × 325 were characterized along with the bulk GACs.

Anion Exchange Resin and Inorganic Anion Parameter Determination for Model Validation and Evaluation of Unintended Consequences during PFAS Treatment.

When implementing anion exchange (AEX) for per- and polyfluoroalkyl substances treatment, temporal drinking water quality changes from concurrent inorganic anion (IA) removal can create unintended consequences (e.g., corrosion control impacts).

Practical implications of perfluoroalkyl substances adsorption on bottle materials: Isotherms.

To assess the practical implications of various bottle materials used in anion exchange (IX) or granular activated carbon (GAC) isotherm experiments, adsorption of seven per- and polyfluoroalkyl substances (PFAS) onto three common bottle materials (silanized glass, polypropylene, and high-density polyethylene [HDPE]) were screened. Results were similar between bottle materials; therefore, only HDPE was used in a detailed bottle material isotherm study with 11 PFAS. For each PFAS, an HDPE bottle isotherm was generated with equilibrium liquid phase concentrations relevant to drinking water (<2000 ng/L).

Occurrence of Per- and Polyfluoroalkyl Substances (PFAS) in Source Water and Their Treatment in Drinking Water.

Per-and polyfluoroalkyl substances (PFAS) occurrence in drinking water and treatment methods for their removal are reviewed. PFAS are fluorinated substances whose unique properties make them effective surface-active agents with uses ranging from stain repellants to fire-fighting foams. In response to concerns about drinking water contamination and health risks from PFAS exposure, the United States Environmental Protection Agency published Health Advisories (HAs) for perfluorooctanoic acid and perfluorooctane sulfonic acid.

Biological nitrogen and carbon removal in a gravity flow biomass concentrator reactor for municipal sewage treatment.

A novel membrane system, the Biomass Concentrator Reactor (BCR), was evaluated as an alternative technology for the treatment of municipal wastewater. Because the BCR is equipped with a membrane whose average poresize is 20 μm (18-28 μm), the reactor requires low-pressure differential to operate (gravity). The effectiveness of this system was evaluated for the removal of carbon and nitrogen using two identical BCRs, identified as conventional and hybrid, that were operated in parallel.

Laboratory evaluation of oil spill bioremediation products in salt and freshwater systems.

Ten oil spill bioremediation products were tested in the laboratory for their ability to enhance biodegradation of weathered Alaskan North Slope crude oil in both freshwater and saltwater media. The products included nutrients to stimulate inoculated microorganisms, nutrients plus an oil-degrading inoculum, nutrients plus compounds intended to stimulate oil-degrading activity, or other compounds intended to enhance microbial activity. The product tests were undertaken to evaluate significant modifications in the existing official United States Environmental Protection Agency (EPA) protocol used for qualifying commercial bioremediation agents for use in oil spills.