(383ag) Poster: Ionic Liquid Membrane for Selective Removal of Nanoplastics from Water: Investigating the Interfacial Interactions between PS Nanoplastics and Dom

Liquid membrane stands out as an effective method for removing contaminants from water. The integration of ionic liquids (ILs), known for their significant stability, water immiscibility, and selective removal capabilities, promises to enhance the effectiveness of the separation process. Nanoplastics, recent emerging contaminants, pose challenges as current wastewater and water treatment processes lack selective and effective removal methods. The interaction between nanoplastics including polystyrene nanoplastics (PSNPs) and humic acid (HA), a complex mixture of organic compounds, presents one of the current challenges in nanoplastics removal. This study explores the use of [C₈C₁Im] [Tf₂N] IL as the liquid membrane for selectively removing PSNPs, focusing on unraveling the intricate interfacial interactions between PSNPs and dissolved organic matter (DOM). The removal of five different types of PSNPs with various functional groups, such as polystyrene (PS), polyvinylpyrrolidone-modified polystyrene (PS-PVP), sulfonated-polystyrene (PS-SDS), carboxylated-modified polystyrene (PS-COOH), and amine-modified polystyrene (PS-NH₂) were studied. The effect of HA concentration, pH, and ionic strength on the binding behavior of PS with HA was investigated. The equilibrium time obtained for the maximum removal of PSNPs with HA was 6 h. The results indicated a significant removal of 84.33% for CPS, 92.64 % for PS-SDS, and 77.67% for PS-PVP in the presence of 10 ppm HA solution. Furthermore, π-π conjugation, dipole-dipole, and ion-dipole interaction were postulated as the binding mechanisms between humic acid and PSNPs, facilitating the transportation of humic acid into the [C₈C₁Im] [Tf₂N].