Abstract:

Humic acid in soil plays an important role in transfer of hydrophobic organic compounds such as polycyclic aromatic hydrocarbons (PAHs).Humic acid can be coated onto some carriers，and its adsorption performance is of great concern.In this study，glass beads in four different size ranges (37—63 μm，105—125 μm，177—250 μm,350—500 μm) were used as the carrier and coated with humic acid extracted from natural soil.The lab-scale experiment for phenanthrene adsorption was carried out.The distribution of phenanthrene in solid and water phases was in accordance with Freundlich isotherms，which implies that larger total surface area (TSA) leads to higher coating efficient and adsorption capacity.However，when the ratio of Freundlich capacity parameter to coating efficiency was used to evaluate the adsorption performance of humic acid in consideration of TSA，smaller particles (with larger TSA) resulted in a smaller ratio value.This study provides a reference for further studies on improvement of adsorption of humic acids.