Study On The Permeability Function Of Fine Particles And The Interception Effect To Salt Contents

Sewage brought some pollutants in the river matrix-groundwater system experiences aseries of chemical, physical and biological effects,a part of the contaminants will infiltrateinto the deep of matrix along with wastewater, and Eventually into the groundwater,Leading to contamination of groundwater environment. So we can set some artificialobstacles in the matrix to protect groundwater quality, Ultra fine particulate matter sneak intothe river matrix, Not only can play a role to prevent water infiltration, but also can trap part ofthe pollutants in the matrix surface and reduce the pollution of groundwater.Adopted technique way of indoor experiment,chemical experimental analysis andtheoretical analysis，the paper mainly studies the different types of ultra fine matrix effect toinfiltration capacity, the main factors affecting the matrix infiltration, and the interceptioneffect to salt contents. The main results are as follows:1）the influence of different types of ultra fine particles matter on permeability functionof soil matrix was analyzed. contrasted the different impact of three ultra fine particulat（eclay,cement, fly ash） sneaking into matrix on the infiltration capacity.2) Factors affecting the infiltration capacity of the matrix have the addition of tinyparticles,adding method of tiny particles, and adding head of tiny particles, In the cement sneak into the conditions River silt matrix density, texture has different effect on the ability ofthe matrix. Various factors affecting the matrix effect and mechanism of infiltration capacityare different. the delivery head increases,The matrix suction of surface will increase,theinfiltration capacity of the matrix will be larger;Cement sneak amount increases, the porositydecreases, reducing the infiltration capacity, but the process is limited;the way of cementsneaking into matrix has a significant impact on infiltration capacity,12hours after the cementsneaked into matrix, the experimental group dive into water, it has enough time to hydrationreaction,the surface will form a dense structure layer, Further smaller matrix infiltration, so itsinfiltration capacity is less than the test group immediately dive into the water; the increasingof cement sneak head make the increasing of potential gradient of infiltration interface,andthen the infiltration capacity will decrease;by changing the content of clay to change thedriving force of water and the hydraulic conductivity of the matrix, The more matrix claycontent, the heavier texture, the smaller the amount of cement to sneak into,smaller impact onthe infiltration capacity; Matrix density increases, the structure loose its structure change fromdense to loose infiltration capacity for impact from large to small.3)Cement sneak has different interception effect for each salt ion.the cement sneakingweaken the capacity of the solute dispersion and diffusion,so it can effectively reduce thechloride ions into the groundwater after cement sneaking in matrix,the calcium ionsself-generated reacts with sulfate ions,and forming slightly soluble substances,it can alsoclog pores, so it has a good interception effect on the migration of sulfate ion;Cementsneaking can effectively reduce potassium entering the groundwater; the calcium ion isdifficult to move with the water for biggish hydrated radius, and add the cement will producea portion of free calcium ions, so it has less effect on the migration of calcium ion; Cementsneaking into matrix changes the porosity, it have a great interception effect for magnesiumions migrating to the deeper matrix; Cement Sneaking into matrix has a significant influenceon TDS of seeping water.In this study, the main starting point is to reduce pollution of groundwater salinity, thepermeability function of fine particles and the interception effect to salt contents areconducted in-depth research, But most of tests carried out in the room, furthermore they are one-dimensional vertical infiltration, Compared with the complexity of the real situation inthe field, there are certain differences, for this study, we require further more in-depth study.