The Retardation Of Clay On Conventional Hydro-chemical Component In The Leakage System

Today,the shortage and safety of underground freshwater resources have become an important factor that restricts the development of the national economy.The deep underground freshwater production is increasing year by year.Once the shallow saltwater is supplied to the deep freshwater layer,the limited deep freshwater may have the potential to be fully salted.Therefore,in order to develop and utilize inland deepwater freshwater more scientifically and reasonably,it is particularly important to study the retardation of clay on conventional hydro-chemical component.Taking the leakage system in the middle-deep of Jiyang County in the inland plain area as an example,this study uses clay of different depth and brackish water in the study area as the research object.Based on the relevant literature at home and abroad and geological and hydrogeological survey,Through the determination of physical properties of clay and constituent content of clay mineral,groundwater ion composition tests,and groundwater isotope tests,the formation and evolution of the leakage system in the study area is analyzed.And combined with the indoor soluble salt test and high pressure infiltration experiments and adsorption test,the hydrogeochemistry action and retardation process of conventional hydro-chemical component in the clay is revealed,it is concluded that the clay retardation mechanism on conventional hydro-chemical component and of the size of the retardation strength by quantitative analysis.This article through the above analysis and research,draw the following conclusions:?1?According to the soluble salt experiment,due to the retardation of the clay layer,large gap of groundwater conductivity exists in vertical with the characteristics of vertical zonality.And the higher the clay content,the stronger retardation intensity;Lithologic characteristics has a certain influence on groundwater water chemical composition,and in range of 42-122 m,Na⁺,Mg²⁺and Cl^-in the groundwater are greatly influenced by soluble salts dissolved.Main compound salt in the groundwater as the main compound salt in the groundwater is NaCl and Na₂SO₄,the ion components of saline water in the leakage system restrict mutually and have influence each other.?2?Clay minerals expansion,clay particle release,hydrogeochemistry action are the main contribution factors of the clay retardation.The retardation of clay on conventional hydro-chemical component is mainly manifested in the cation exchange adsorption.Under the same pressure,the permeability gradually reduces and salt gets trapped in clay;with the increase of pressure,the permeability coefficient increases,the retardation becomes weak in gradually.It is suggested that the retardation has certain limits.To the clay layer with a large amount of salt accumulated,there is dissolution accompanied in the process of the flow.?3?The isothermal adsorption curve of the different depths of clay to the conventional ions in the groundwater accords with the linear adsorption law of Herry.Generally,the differences of clay mineral content,clay content and salinity of different depth led to the differences of clay adsorption performance.And it is displayed as the higher the ion concentration,the stronger the adsorption intensity of the clay;There is a kind of retardation of different depths of clay to the conventional ions in groundwater and the retardation intensity of the clay to the conventional ions corresponds with the content of groundwater chemical composition.the higher ion content is,the stronger the retardation of clay on.At the same time,the retardation of the clay controls the conventional groundwater chemical composition content in turn.?4?In the pore water system in the study area,from the formation and evolution of the leakage system,the changes of chemical composition,type of water chemistry and groundwater conductivity several aspects,the aquifers of different depth in vertical have obvious zonality features.This is due to the clay layer structure between of the aquifer layers cuts off the connection between adjacent aquifers,then make the groundwater with different recharge sources can maintain the stability of water quality and water level differences.Through the retardation on conventional ions,the clay controls the vertical zonality of water chemical composition pore in water system in the study area.