Membrane-assisted photocatalytic degradation of perfluorooctanoic acid

Abstract

The ubiquitous presence of per- and poly-fluoroalkyl substances (PFAS) in the environment together with their persistence urges the development of cost-effective remediation technologies to be applied to their aqueous sources thus, preventing their entrance to nature. Among all PFAS, perfluorooctanoic acid (PFOA) has been identified as a substance of very high concern due to its extreme persistence, bioaccumulation, and mobility in the environment; however, conventional technologies for water remediation report low yield in PFOA degradation. Photocatalytic degradation reports outstanding characteristics in its application to the degradation of recalcitrant compounds. This alternative relies on the properties and characteristics of the semiconductor material used as a photocatalyst, a fact that has prompted a series of works related to the synthesis and viability of new catalysts in recent years. After the preliminary results obtained in our group with a new composite photocatalyst based on the combination of the more extended TiO2 P25 semiconductor with reduced graphene oxide, TiO2-rGO 5%, this work provides a deeper analysis of the influence of operation conditions on the degradation kinetics and highlights the relevance of a membrane pre-concentration step, especially for the removal of aqueous matrixes with low PFOA concentration.