Mr. Fenstermacher is an OBG thought leader on the fate, transport, and remediation of per- and polyfluorinated alkyl substances (PFAS). He is a member of Ramboll's Emerging Contaminant Initiatives team and regularly interfaces with academia, providing branding, business development, and subject matter expertise on PFAS. He has a Bachelor’s degree in Chemical Engineering from Worcester Polytechnic Institute, a Master’s degree in Civil-Environmental Engineering from the University of New Hampshire, and provides project teams across Ramboll with technical and subject matter expertise and supports business and organic growth priorities within the organization.
Evaluation of Removal Efficiencies from Multiple Stand-Alone and Combined PFAS Treatment Processes
Ramboll is evaluating multiple treatment technologies at the laboratory-scale for treatment of landfill leachate that will involve treatment of raw landfill leachate via dissolved air floatation (DAF), PFAS-specific coagulation/precipitation, membrane filtration, activated carbon adsorption, and plasma destruction. These technologies are being evaluated on a stand-alone basis and in combination in a blocked experimental design whereby we are evaluating the treatment efficacy of (for example) coagulation/precipitation alone for removal of PFAS, and as a pretreatment step for activated carbon adsorption to evaluate increases in treatment efficiency and operational bed life. Stand-alone and multi-step treatment processes (i.e., treatment trains) evaluated include: DAF treatment alone; coagulation/precipitation alone; coagulation/precipitation followed by DAF clarification; coagulation/precipitation followed by activated carbon adsorption; ultrafiltration followed by activated carbon adsorption; ultrafiltration followed by nanofiltration; ultrafiltration followed by reverse osmosis; and ultrafiltration followed by reverse osmosis with plasma destruction of the membrane reject stream. Analytical data collected includes total dissolved solids, total organic carbon, quantitation of 24 individual PFAS (the Michigan minimum laboratory analyte list), and Total Oxidizable Precursor Assay. The presentation will review pre- and post-treatment data, with comparisons of stand-alone and combined treatment efficiencies, including observed PFAS selectivity (e.g., preferential removal of PFSAs in comparison to PFCAs) and total PFAS removal. Because the aqueous matrix was a landfill leachate with starting a total PFAS concentration ranging from 600 to 1,000 ng/L with a low-pH/high organic background, the combined remedy and individual treatment effectiveness results are expected to be highly portable and informative to treatment of virtually any aqueous matrix.