Technological advances in per- and polyfluoroalkyl substances (PFAS) removal from landfill leachate: Source identification and treatment options

Per- and polyfluoroalkyl substances (PFAS) are a group of persistent organic compounds that present significant risks to both environmental systems and human health. The increasing concentration of PFAS in landfill leachate has been an emerging concern for waste management. This article presents a critical review of the current state-art of the technologies and processes for PFAS removal from landfill leachate. The article primarily addresses two aspects: (a) identifying the primary sources contributing to PFAS leaching, which includes examining various waste streams such as municipal solid waste (food packaging products, household consumer goods, cosmetics, electronic components), construction and demolition debris, and industrial waste (bio-solids, incineration ash, and manufacturing waste); (b) evaluating different technological options for PFAS removal from leachate, such as adsorption techniques, membrane filtration, electrochemical oxidation, photocatalytic oxidation, and biological treatment. The findings showed that the PFAS concentrations across different MSW components varied significantly, ranging from as low as 0.1 ng/L to as high as 150,000 ng/L, depending on the PFAS type and source. Additionally, the article explores the factors influencing the performance of these treatment technologies based on the experimental results, development stage, reaction time, and removal efficiency. Adsorption (granular and magnetic activated carbon) and membrane filtration processes have demonstrated higher PFAS removal efficiency ranging from 70 % to 95 %. This study emphasized the need for effective PFAS treatment strategies while addressing ongoing challenges and future research directions in mitigating their environmental impact.