Emily Crownover, Ph.D.
TRS Group, Inc.
Dr. Emily Crownover is a lead engineer at TRS overseeing engineers supporting thermal remediation projects through site design, construction, operations, and research and development. She is also co-inventor on a PFAS thermal treatment. Emily joined TRS after obtaining her Ph.D. in Bioengineering from the University of Washington-Seattle. Dr. Crownover leads the TRS research and development program including PFAS treatment in water and soil, 1,4-dioxane remediation, and low temperature heating to enhance degradation pathways.
Treatment of Per- and Polyfluoroalkyl Substances in Soil and Water
Per- and polyfluoroalkyl substances (PFAS) comprise an extensive group of closely related chemical compounds, which were manufactured in large quantities over the course of several decades. As PFAS are among the strongest organic compounds, they are generally considered non-degradable, due to their persistence in the environment. Because PFAS tend to be highly soluble, they do not favorably partition into the vapor phase, nor do they adsorb terribly well to sorptive media, such as granular activated carbon (GAC) or ion exchange resins (IX), which remain the most commonly used methods to treat PFAS-contaminated water. Thus, practitioners have difficulty remediating these compounds at a reasonable cost. The PerfluorAd system, followed by sorptive media polishing, is an innovative process for the treatment of PFAS contaminants in industrial and municipal wastewater, AFFF-impacted groundwater, fire-fighting equipment and storage vessels and landfill leachate. The costs for PerfluorAd compare very favorably to GAC and IX systems. Further, PerfluorAd works well removing high concentrations of PFAS and is more effective than sorptive media for short-chain PFAS. Significantly, the PerfluorAd system performance is unaffected by the dissolved organic carbon or other contaminants in the treatment water. PFAS are precipitated through a weak ionic bond with the liquid PerfluorAd-active compound that is metered into a stirring tank. The amount of PerfluorAd is adjusted to varying concentrations based on several parameters. The precipitation products are separated from the water as micro-flocks by simple processes such as sedimentation and filtration. The precipitants can be concentrated to a very high degree, which allows for economical disposal. Polishing treatment of any remaining, minor amount of PFAS is performed by a downstream GAC or IX filter, significantly extending the adsorptive capacity of the GAC or IX media.