Poly- and perfluoroalkyl substances (PFAS) are a large group of organic contaminants that have been detected nationally in the aquatic environment. Two PFAS compounds, perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS), have been observed in >95% of the blood samples collected during multiple U.S. national surveys at health-relevant concentrations. Contaminated drinking water is a major source exposure to PFAS for the general public. The U.S. EPA has recently set a drinking water advisory on the combined level of PFOA and PFOS at 0.070 μg/L, making removal of PFAS from drinking-water sources a priority issue.

The goal of this project is to develop an innovative treatment system that can effectively and practically remove PFAS from landfill leachate and groundwater. The leachate samples were pretreated to simulate a typical wastewater treatment setup using flocculation/coagulation and ozonation. The fate of PFAS throughout the entire process is identified. We also performed experiments on the adsorption of PFAS using various commercially available granular activated carbon (GAC) samples using DI water, surface water and leachate. We also tested the decomposition of PFAS using thermal treatment techniques discussed in our previous publications on leachate samples.

The results of this project have important implications for technological improvements in water purification. Water treatment plants, the water industry, water resources personnel, and the broader education and research communities who are concerned about PFAS contamination would benefit from the results of this proposal.

Publications:

Thermal stability and decomposition of perfluoroalkyl substances on spent granular activated carbon, ACS ES&T Letters, 2020

Production of granular activated carbon by thermal air oxidation of biomass charcoal/biochar for water treatment in rural communities: a mechanistic investigation, Chemical Engineering Journal Advances, 2020

Thermal decomposition of anionic, zwitterionic, and cationic polyfluoroalkyl substances in aqueous film-forming foams, ACS ES&T, 2021

Effect of granular activated carbon and other porous materials on thermal decomposition of per- and polyfluoroalkyl substances: Mechanisms and implications for water purification, Water Research, 2021

Conference Proceedings

Oral Presentation - CHALLA SASI, P., ALINEZHAD A., XIAO F., BIN, Y., KUBÁTOVÁ, A. GOLOVKO, S., GOLOVKO 2021. “PFAS thermal decomposition: Effect of GAC and other porous materials.” American Chemical Society.

Oral Presentation - CHALLA SASI, P., ALINEZHAD A., XIAO F., BIN, Y., KUBÁTOVÁ, A. GOLOVKO, S., GOLOVKO 2021. “PFAS thermal decomposition: Effect of GAC and other porous materials.” Society of Environmental Toxicology and Chemistry.

Poster Presentation - CHALLA SASI, P., XIAO F., “Destruction of “Forever Chemicals” ND EPSCoR Annual Conference.

Oral Presentation - CHALLA SASI, P., ALINEZHAD A., XIAO F., BIN, Y., KUBÁTOVÁ, A. GOLOVKO, S., GOLOVKO 2021. “Thermal decomposition of PFAS on spent GAC and their implications of drinking water”. Universities Councils on Water Resources/ National Institute for Water Resources.

Oral Presentation - CHALLA SASI, P., ALINEZHAD A., XIAO F., BIN, Y., KUBÁTOVÁ, A. GOLOVKO, S., GOLOVKO 2021. “Thermal treatment of PFAS in Aqueous Media”. Inaugural North Dakota Regional Environmental Conference, Air and Waste Management Association – Upper Midwest Section.

Notable Achievements and Awards:

Received 2^nd prize at 3MT (3-minute Thesis) competition held at University of North Dakota for a presentation on Destruction of “Forever Chemicals”.