Abstract:Control of pollutant migration is the prerequisite for the reuse of contaminated soil. Considering the properties of contaminated saline soil and the mechanical demand in engineering utilization, lime and fly ash were chosen optimally as treated materials. The influence of lime and fly ash on adsorption-desorption behaviors of oil contamination in inshore saline soil were studied via static and dynamic tests. Results indicate that:under the individual action of lime and fly ash, the oil adsorption rate is increased by 26% and 14%, respectively, and it increases by 39% as combine. As a conclusion, lime and fly ash can effectively increase adsorption rate and improve adsorption rate of oil contamination. Adsorption kinetics of saline soil, lime + saline soil, fly ash + saline soil, lime + fly ash + saline soil on oil contamination conform to the dynamic nonlinear equation of Lagergren second-level dynamics. The adsorption equilibrium time of saline soil was 400 min and it reduced to 60 min for lime and fly ash. Lime and fly ash is beneficial to adsorb the free oil which cannot be adsorbed by saline soil. The adsorption isotherms of saline soil, lime + saline soil, fly ash + saline soil, lime + fly ash + saline soil are non-linear Freundlich models. Adsorption of oil contamination for lime + fly ash is an irreversible chemical process, which can help to reduce the influence of ambient temperature and enhance stability.