Study On The Effect Of Colloidal Particle Size Ratio And Concentration On Polymeric Colloid Transport

Colloid refers to some macromolecules or very fine material particles in the range of 1 nm to 1 μm in size.Colloids are widely distributed in the groundwater environment.They have different sizes and different concentrations.Due to the large specific surface area of colloids,Contaminants show higher affinity for colloids than solid-phase matrix surfaces.Therefore,colloids can be carried as carriers of pollutants for migration.Therefore,studying the colloidal migration process has important environmental significance.There are many factors that affect the migration of colloids,mainly colloidal concentration,colloidal particle size,solution pH,solution ionic strength,water flow rate and so on.In the current theoretical research,most of them only study the single factor,and most studies on the colloidal particle size use a single particle size colloid.There are two or more different particle size colloids studied less.In this paper,we mainly study the migration of polydisperse colloidal systems at different particle size ratios and different concentrations under the conditions of simulated underground aquifer media,and discuss their mutual influence.Through laboratory simulation experiments,the data are analyzed in depth Conclusion,in order to fill the polydispersity system,the size of the particles how to influence each other gaps and deficiencies.The target materials were latex beads of 50 nm,200 nm and 500 nm with different particle sizes.Through the two-by-two mixed penetration column experiments and their control experiments(each group of experiments and control experiments were done three times average),draw a breakthrough curve of each latex ball.By discussing the results of their breakthrough curves,the following conclusions can be drawn:(1)The presence of larger particles at high concentration is a blocking effect,which appears to be a clean bed deposition at low concentrations,probably because the concentration of colloids is significantly reduced while the number of spots is constant,so there is no need for competition to allow efflux Concentration tends to be stable,so the adsorption rate remains unchanged.(2)Small particles can promote the flow of large particles,and the larger the particle size ratio,the smaller the effect of small particles on the outflow of large particles,the reason may be that small particles are easier than large particles to seize the point,and the larger the particle size ratio lead to small particles occupy the point,the gap between them is not enough to make large particles settling or adsorption,affecting the deposition of large particles,leading to large particles outflow.(3)Regardless of the high and low concentration,while the size of particles,large particles will inhibit the outflow of small particles,and the smaller the particle size ratio,large particles on the inhibition of small particles,the reason may be large particles produced shadow area,while the smaller the larger the particles,more likely to settle in the shaded area,so the flow out less.(4)Regardless of the level of concentration,the co-migrating effluent mass concentrations of the two different particle size colloids are consistent with the single particle size colloidal migration results.