Executive Summary : | Perfluoroalkyl substances (PFAS) are recalcitrant pollutants of emerging concern with high toxicity, mobility, and bioaccumulation, resulting in potential adverse effects on the environment and human health [1]. The primary application of PFAS includes firefighting foams, textiles, food packaging, detergents, and cosmetics, which was reported by the European Chemicals Agency (ECHA). PFAS have been detected in surface water [2], groundwater [3], air [4], soil [5], plants [6], and in human blood from ng/L to µg/L levels [7]. As a result, the PFAS in water systems exhibits additional toxic properties along with the hydrocarbons, chlorinated solvents, solvent stabilizers, and fuel components. Recently, more than 2,000 individual PFAS in the EU market has been reported according to the ECHA database. Furthermore, the recent studies from the Organization for Economic Co-operation and Development (OECD) identified almost 5,000 PFAS, and the Swiss Federal Institute of Technology (ETH) Zurich found more than 200 specific uses for 1,400 PFAS which was identified in the EU. Therefore, major European countries such as the Netherlands, Germany, Norway, Denmark, and Sweden have decided to submit a PFAS restriction proposal to ECHA by 15 July 2022 [8-9]. Besides, Environmental Protection Agency (EPA) and EU Water Framework Directive (EU, 2013) set PFAS Environmental Quality Standard (AA-EQS) limit value as 0.5 µg/L in drinking water. The European Chemical Agency added perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS), and hexafluoropropylene oxide dimer acid (GenX) to the European Union watchlist for substances of very high concern in 2019 [10-11]. Conventional tertiary treatment technologies viz; chlorination, UV treatment, ozonation, sand filtration, coagulation, and membrane filtration are not effective and efficient in removing low concentration pollutants such as PFAS [12-14]. Advanced oxidation processes (AOPs) for effective removal of emerging contaminants are in recent trends [15]. Wastewater treatment using electrochemical methods is an emerging technology for the destruction of PFAS that is significantly important as national and international regulations rightly tighten. The main concept is to convert a target pollutant of PFAS to a harmless by-product via either direct oxidation/reduction or in-situ generated reactive oxygen species at the anode, which in turn will attack the pollutant. Recent scenario, the most investigated anode for PFAS removal is the boron-doped diamond (BDD) [16]. However, the cost of the BDD electrode makes it unreliable for large-scale applications. Therefore, the research is aimed to develop a low-cost anode for the effective removal of the PFAS in water. |