Research on adsorption behavior of Phenanthrene on anti-permeation clayey soil in Landfill

Adsorption of Phenanthrene in anti-permeation clay in Landfill was studied in this investigation. Through a series of lab experiments, adsorption mechanism and models were studied, as well as influential factors such as pH and particle. The main conclusions reached are five: (1) Sorption of Phenanthrene in clay soil followed a four-phase process (fast-slow-equilibrium-desorp ion), and the time reached equilibrium was nine hours. (2) The sorption isotherm consisted better with Freundlich model, and correlation coefficient was 0.98. So it was accounted as the non-linear isothermal adsorption. (3)The partition coefficient of Phenanthrene (Kd) between soil and water was 0.01, and the partition coefficient between organic carbon and water was 14.29. (4) pH>;7.42, the adsorption capacity of soil samples increased rapidly with the alkaline rising; pH<7.42, it would increased as the former, but if pH<6.74, the adsorption capacity was no longer changed significantly. (5) The content of clay and specific surface area played important roles in sorption. The descending order of adsorption in samples was clay>; silt clay>; fine sand.