Colorado School of Mines
Conner is a PhD student from Colorado School of Mines working under Dr. Chris Bellona.
Bench scale evaluation of granular activated carbon and ion exchange resin for removal of per- and polyfluoroalkyl substances
Per- and polyfluoroalkyl substances (PFASs) are emerging contaminants found in numerous aquatic systems across the United States and other countries. Numerous PFASs have been quantified in municipal drinking water supplies serving as an exposure route for city residents. Of the hundreds of PFASs that are currently known and studied, perflurorooctane sulfonate (PFOS) and perflurorooctanoic acid (PFOA) have received the most attention due to their relatively common occurrence in the environment, recalcitrance in treatment and associated human health concerns. The USEPA recently developed a health advisory limit of 70 ng/L for PFOS and PFOA combined or separate in 2016. Perfluoroalkyl acids (PFAAs) such as PFOA, PFOS are noted for being poorly removed by conventional drinking water treatment processes due to their stability corresponding to strong C-F bonds. Adsorption onto granular activated carbon (GAC) and ion exchange resin (IX) has evolved into a promising treatment approach for PFASs capable of removing trace levels of contamination in water treatment applications. Unfortunately, there is currently little guidance on the selection of adsorptive technologies for PFAS removal, and a comparison of the different approaches through literature is difficult due to differences in experimental conditions including contaminant and co-contaminant levels, water sample background matrices and limitations in experimental setups. The objective of this study is to evaluate the PFAS removal performance of GAC and IX resin in a continuous flow column system that utilizes full-scale media while at the bench scale to accelerate the observed breakthrough. Columns will be operated in series to simulate the performance of multiple adsorption zones within a single column while also incorporating hybrid designs to determine how different media orientations impact PFAS removal performance. Results from this study will highlight the effectiveness of lead/lag adsorption configurations with GAC and IX resin in the removal of a broad suite of PFASs while also assessing the effectiveness of using a lab scale column design for predicting full scale performance.