PFAS Unit Process Wastewater Treatment Proposal

Per-/polyfluorinated alkyl substances (PFAS) are a family of contaminants causing growing concern. They are used in many industries and consumer goods because of their compound stability and hydrophobic, oleophobic and hydrophilic functionalities. But research suggests that exposure to PFAS can be harmful to health. This project uses a tertiary wastewater unit process to remove PFAS via adsorption to granular activated carbon (GAC).

The design consists of GAC adsorption columns, placed in parallel and lead-lag configuration to reduce the flow rate and increase the wastewater’s contact time without drastically increasing the overall retention time. The team conducted an experiment to determine the breakthrough properties of GAC with the PFAS in order to improve modeling of the process. The improved model allowed for a more accurate prediction of compound removal and GAC replacement requirements. The design effectively adsorbs the PFAS compounds and produces clean effluent water with a concentration safely below the recommended EPA standard of 70 ppt.