Density Functional Theory Investigation of the PFAS adsorption on Metal Modified Biochar

Recently, Per- and Polyfluoroalkyl substances, commonly known as PFAS, has been one of the most widely researched topics with the awareness of their hazardous effect on human and environmental health. Most notably, researchers have shown keen interest in the removal of PFAS from the aqueous system via adsorption. However, due to the complexity and cost of most manufactured adsorbents, nature abundant materials like biochar have taken a highlight. Unfortunately, lack of understanding on the fundamental behavior of biochar limits its development as an effective and efficient PFAS adsorbent. Therefore, we have conducted Density Functional Theory (DFT) based calculations to uncover the fundamental mechanisms governing the adsorption of PFAS onto the biochar surface. Significantly, the effectiveness of incorporating atomically dispersed transitional metal ions in the biochar matrix as a novel strategy to enhance the adsorption of biochar has been studied by carrying out DFT calculations on the molecular systems. We will present the discovered kinetic and structural behavior of selected PFAS molecules on the surface of metal incorporated biochar and discuss the fundamental principles that might possibly lead to the development of more efficient PFAS adsorbents.