Surfactant Repairs Soil Heavy Metal Pollution Research

Because of the difficult degradation,transference,high toxicity and the function of accumulation,the soil which polluted by heavy mentals causes serious damage to human health and ecological environment.In various kinds of soil environmental restoration method,chemical removal contaminants is one of the important repair technology,and the choice of rain lotiong is the key of the technology of soil removal contaminants.Take three kinds of surfactant,anionic surfactant dodecylbenzenesulfonic acid,sodium dodecyl sulfate and non-ionic surfactant(Tween-80)to remove the heavy mentals of Cr,Pb,Cd in the soil samples.Researching the efficiency of heavy mentals removal influenced by the concentration and the composite function of the three kinds surfactant with the two text methods oscillation and leaching.Spectrometric analysis the shape of heavy mentals in the soil before and after it disposed by surfactant,and set up the thermodynamics equation of surfactants during the process of adsorption of the soil.In addition,this experiment also take the infrared spectral analysis to the complex makes up by lauryl benzene sulfonic acid and cadmium.The experimental results show that surfactant used to remove the heavy mental in the polluted soils has obvious effect,it has a best removal effect when the concentration of surfactant is around the critical micelle concentration.When the concentration of dodecylbenzenesulfonic acid is 1.0g/L,the removal rate of Cr,Cd and Pb are 81.1%,33.2%and 4.6%.When the concentration of dodecylbenzenesulfonic acid rise to 2.5g/L,the removal rate of Cr,Cd,Pb reach to 79.91%,11.97%and 3.37%.It is show that the removal rate of heavy mental is influenced by the concentration of leacheate and the rate rises with the concentration of leacheate rise.When the soil contains various of heavy mental,it will has antagonist effect to surfactant and reduces the removal rate of heavy mental greatly.After compared the analysis results of different shape of heavy mental in the soil which is disposed by surfactant it shows that the capacity of dodecylbenzenesulfonic acid to remove different heavy mental has discrepancy,especially for Ion exchange state and carbonate combination state metal.Infrared spectroscopy testing results show that the reaction of dodecylbenzenesulfonic acid and mental ion forms coordination compounds.Moreover,surfactant in soil column adsorption experiment shows that the adsorption of surfactants is linear related,the adsorption quantity increases with the rise of the concentration of surfactant,and different kinds of surfactant has different adsorptive functions.The thermodynamic equation of surfactant used in soil fit the Freundich isothermal adsorption equation.Metal ions and anionic surfactant can form soluble complex through the function of complexation directly or be transferred to surface active agent solution phase through the baker or adsorption effection and then removed out from the soil.Using the dodecylbenzenesulfonic acid,sodium dodecyl sulfate and non-ionic surfactant(Tween-80)to as the leacheat can remove the heavy mental in the polluter soil effectivily,and this method operate easily and has low processing cost.