The Research On Adsorption Kinetics And The Retardation Factor Of Persistent Organic Pollutants-heptachlor In Sediments Of Weihe

Persistent organic pollutants means human synthesis and accumulation throughthe food chain, they are persistent chemicals in the environment, and cause harmfuleffects on human health. It has four characteristics: biological accumulation, dear lipidhydrophobic, highly toxic, persistent, on human health and environment has itsserious harm. Heptachlor (C10H5Cl7) is a kind of widely used OCPs, in manycountries have banned or restricted use for many years, but the sediment as a majorenvironmental fate heptachlor transfer and transformation, there are still some residualconcentration.This experiment will be collected from the Weihe River marsh sampling points atone meter sediment sand as pollution receptor, static adsorption experiment and soilcolumn simulation experiment will be doing in the laboratory under controlledconditions, and systematic study its adsorption behavior and influence factors in thesand so that we can know its migration in the special environment, and calculate theretardation factor.This research laid the foundation for the heptachlor prevention project, providesthe reference for the study of heptachlor migration in the environment.The final conclusion is:1. Dynamic adsorption test: the fast adsorption stage of heptachlor in the sampleis not more than4hours, in about the eighth hour the adsorption comes to slowequilibrium, the isothermal adsorption reached apparent equilibrium time is not morethan18h;2. Batch equilibrium experiments show: In0~1mg/L concentration range westudied heptachlor balance behavior experiment, using Freundlich equation can verygood fitting its linear adsorption isotherm, Kd values of12.84ml/g, Rd value is140.6.3. Factors influencing the particle size, organic matter content, initial solutionconcentration, pH on the adsorption results show: with the decreasing of particle size,organic matter content increases, the initial solution concentration, the increase of PH,the adsorption of heptachlor in the sample have different concentration increases. 4. The soil column simulation experiment: In this experiment, Cl＿as a tracermaterial, we can get Cl＿breakthrough curves under the steady flow conditions. Infour months time, we did leaching dynamics experiment of heptachlor in the sample,obtain the curve of vertical concentration distribution in the soil column. The resultsshowed: the concentration peak of heptachlor appears in the soil column is about16cm, the dynamic block factor value is58.93.