Per- and Polyfluoroalkyl Substances (PFASs) Removal from Landfill Leachate : Efficiency Evaluation in Column Experiments

Abstract: Per- and polyfluoroalkyl substances (PFASs) are known for their wide spread in the environment, their persistent properties and their ability of biomagnification through the food chain. With properties such as oil and water repellence, temperature resistance and a long lifespan they have been frequently used in various areas, e.g. hygiene products such as shampoo and tooth paste as well as in the firefighting industry as firefighting foam. They are therefore commonly found in leachate from landfills. Up to now, there is a lack of studies investigating methods of how to treat PFAS-contaminated leachate and hence more research in this area and development of suitable treatment technologies is needed. In this study, column experiments with granulated activated carbon (GAC), anion exchanger (AE) resin and peat mixed with ash were performed. The results showed that AE removed PFAS more efficiently than GAC, that longer chains had a higher sorption ability than shorter chains and that perfluorinated sulfonic acids (PFSAs) a higher sorption ability than perfluorinated carboxylic acids (PFCAs). The peat-ash columns had a slower flow and only 5bed volumes (BVs) of leachate were treated. Hence, these results could not be compared with GAC and AE. For GAC and AE 1920 BVs and 1840 BVs, respectively, were treated and none of the filters got fully saturated. The conclusion of the study is that AE is likely a more suitable treatment technology for this purpose than GAC but more research is needed to determine the breakthrough and design PFAS treatment for leachate.