Anaerobic digestion supplemented with carbon materials as a sustainable approach for the bioremediation of PFAS

Abstract

Per- and polyfluoroalkyl substances (PFAS) are recalcitrant fluorinated organic compounds that tend to persist in soils and aquatic ecosystems and cause adverse effects on the environment and human health, so its remediation is crucial. Anaerobic digestion (AD) mediated by carbon materials (CM), has shown high efficiency in the removal of organic pollutants from wastewater. In this work, the feasibility of applying AD in the bioremediation of PFAS was studied. Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) were evaluated. These compounds promoted an inhibition in the activity of acetoclastic methanogens and acetogenic communities below 15 %, at a concentration higher than the usually found in wastewater treatment plants (WWTP) (0.1 mg L-1), while hydrogenotrophic methanogens were not affected. When supplementing AD of PFAS with CM the negative effect was reduced. Moreover, the methanization percentage of sewage sludge contaminated with PFAS increased 41 % in the presence of 1.2 g L-1PFOS and AC, demonstrating the benefit of bringing AD and CM together for PFAS bioremediation.