Petroleum Hydrocarbon Transport through Saturated-unsaturated Media :A Numerical Model and Practice

摘要

The mathematical model of migration of total petroleum hydrocarbons in unsaturated media was described,including convection,molecular diffusion,mechanical dispersion and adsorption,and chemical reactions.By finite element method,a numerical model of evaluating petroleum hydrocarbon migration through contaminated soils was created and applied to the environmental investigations of a relocated mechanical factory in Shanghai.The model consisted of three compacted soil layers:plain fill,sandy silt and silty clay.The results showed that pollutants in the sandy silt traveled faster than that in the plain fill and silty clay.The same decreasing trend of migration velocity was observed in all of the three soil layers.After 180 d,the concentrations of pollutants in the sandy silt can be as low as 40% of the original maximum,while its counterpart in the silty clay is 64%.