Transport and retention of polymer-stabilized zero-valent iron nanoparticles in saturated porous media: Effects of initial particle concentration and ionic strength

This study investigated the transport and retention of polyacrylic acid and polyvinylpyrrolidone stabilized zero-valent iron nanoparticles (PAA-ZVIN and PVP-ZVIN) in saturated porous media. The transport experiments were conducted in sand packed columns. The breakthrough curves (BTCs) and retention curves of ZVIN were analyzed. Results of transport experiments showed that increasing initial particle concentration and ionic strength led to a decrease in ZVIN transport. The zeta potentials and hydrodynamic diameters of PAA-ZVIN were apparently more negative compared to PVP-ZVIN. Results indicated that some mechanisms such as aggregation, ripening, and surface roughness had considerable impact on ZVIN retention in porous media.