The Research On Adsorption Characteristics And The Dial Mode Retardation Factor Of Decachlorobiphenyl In Sediments Of Weihe

Decachlorobiphenyl belongs to persistent organic pollutants. Because it has the characteristics of environmental persistence, semi-volatility, bioaccumulation and high toxicity.Once decachlorobiphenyl enter the natural environment, it will bring about serious influence to the environment, and make a threat to the human production and living. So it is important to research the rule of transportation and conversion of decachlorobiphenyl.This paper make the sediment sand sample as the receptor of the pollution, after understanding the hydrology and geographical conditions of this region, conduct static absorption experiment and live migration experiment, study adsorption characteristics, influence factors and migration rule of decachlorobiphenyl in the sediment sand sample, work out the dial mode retardation factor.The final conclusion of this study is:1.The adsorption kinetics experiments show that the time of fast adsorption period of decachlorobiphenyl in weihe sediment is from beginning to the second hour, when the fourth hour,the time of slow equilibrium of adsorption start from the fourth hour, form the 8th, the isothermal adsorption reached apparent equilibrium.2.In a certain concentration range, we study batch equilibrium adsorption experiments of decachlorobiphenyl, and use different adsorption model for adsorption isotherm fitting. The study shows that dual mode model which is combined linear model with Langmuir model can describe the isothermal balance adsorption course of decachlorobiphenyl in weihe sediment better.Meanwhile the study conclude static retardation factor, and derive dual mode retardation factor by the inversion.3.The study about influence factors of adsorption for decachlorobiphenyl in weihe sediment shows that: When the size of sand sample is bigger, the adsorption capacity of decachlorobiphenyl in weihe sediment is greater. When the organic content of weihe sediment is higher, the adsorption capacity of decachlorobiphenyl in weihe sediment is greater. In a certain pH range, when the pH value is higher, the adsorption capacity of decachlorobiphenyl in weihe sediment is greater. The higher of initial feed concentration of decachlorobiphenyl, the greater of adsorption capacity of decachlorobiphenyl in weihe sediment.4.The kinetics of desorption experiments show that the time of fast desorption period of decachlorobiphenyl in weihe sediment is from beginning to the second hour, when the fourth hour,the time of slow equilibrium of desorption start from the fourth hour, form the 8th, the isothermal desorption reached apparent equilibrium. Isothermal equilibrium desorption experiments showed:When the inital adsorption quantity increased, the desorption quantity of decachlorobiphenyl in weihe sediment increased. Meanwhile, the desorption process of decachlorobiphenyl in weihe sediment is hysteretic.5.The dynamic migration experiment: In this experiment, we take Cl- as a tracer element to get breakthrough curves of Cl- under the steady flow conditions. we go ahead the dynamic migration experiments, get the migration rule of decachlorobiphenyl in the sand colum, obtain dynamic retardation factor of decachlorobiphenyl.