SDS and TX-100 performance in removing Cd ion from contaminated sand in flushing column

Abstract

In this study, contaminated sand by cadmium (Cd2+) ion was cleansed by surfactant foam in a flushing column. The ability to remove Cd2+ ion on the sand surface influenced by the surfactant's properties. The Sodium dodecyl sulfate (SDS) as an anionic surfactant was compared with Triton X-100 (TX-100) non anionic surfactant in their ability to remove the metal ion on the sand surface in the flushing column. The loading time, surfactant concentration, and flow rate of the surfactant were then investigated to confirm the charging effect of surfactant in the ability to remove metal ions. The results show that SDS has a higher ability than TX-100 to remove the Cd2+ ion on the sand surface. The optimal removal efficiency by SDS was 52 %, and TX 100 was 47 %. The loading time impacted surfactant interaction with metal ions in the column, showing that a longer loading time will increase the removal efficiency. Increased concentration of surfactants and more prolonged initial flushing tend to remove higher metal ions, indicating that the residual metal ion was flushing out on the first four pore volume removals. Flushing in a column with foam by anionic surfactant shows a higher ability to remove metal ions on the sand surface.