Study On Sorption Behavior Of TCE By Natural Soils And Sediments

The soil/sediment is an important part of Wter enviorment system, is the carrier of multitudinous pollutants, the home to return to which migrates and stores in the environment. Along with the organic matter type increasing and the industry development, the soil/sediment pollution already became an environment question in the world scope. This article take the trichloroethylene as a representative organic matter, make a system research of the soil/ sediment's adsorption behavior characteristics to volatilitile organic pollutant.The sorption characteristic of soil itself is also researched in the numbers.The following were the main results.Under this experimental condition, 10 kind of soil samples to the TCE adsorption equilibrium test results indicated that adsorptive capacity mainly related with soil organic carbon content in entire experimental concentration scope.Three surface soils with rich organic carbon,the isotherms of TCE was linear, R2 of TCE were 0.9738～0.9910.Three Geochemical Standard Reference Samples of soil(GSS) and one Geochemical Standard Reference Samples of Drainage Sediment(GSD), the isotherms of TCE was linear, R2 of TCE were 0.9754～0.9970.While three underground water with poor organic carbon,the isotherms were nonlinear, which can be described with Langrnuir equation, R2 of TCE was 0.8982～0.9426.The structure of organic carbon was hardly inflected to the sorption on TCE.The partition coefficient(normalized to organic carbon) logkoc of the samplesand sub-samples for TCE were all 2.086±0.168～.295±0.078.This proved that the incompact carbon aggregation and the compact carbon aggregation haven same adsorptive capacity on TCE.The particle contents of soils was not correlative with the sorption ,however the total organic carbon(foe) was correlative with the CEC,and the relation of foc and CECon soils of unsaturated zone was CEC=5.4563(foc)+5.6051,R2=0.8921. The relation of focand CEC on soils of GSS and GSD was CEC = 10.651(foc)±2.4928,R2 = 0.9382.TCE was hardly absorbed by the quartz and kaolinite.In the experiment systems,the sorption percents of TCE was 5%～50%.The percents in solution of TCE was 30%～60%.The volatilization percents of TCE was also up to a third.The total sorption capacities of organic carbon on TCE equal to the sorptioncapacities of incompact carbon aggregation and the compact carbon aggregation.