Study On Nitrobenzene Breakthrough Experimental In Sand Medium

Based on the background of the nature science fund "Modeling and research of the effects of river pollution on ground water",sand medium of the Wei river is selected to be the study object,and the systematic study on nitrobenzene breakthrough experimental in sand medium is launched.Using the way combining laboratory experiment and numerical simulation to In-depth study the Internal law nitrobenzene penetrating in sand medium and reveal through the process of sand of medium on adsorption characteristics of nitrobenzene and modified the model of the breakthrough curve to the theoretical basis of mass conservation and analysis model parameters on the sensitivity factors (Concentration, flow, penetration height and penetration media), the results show that:1.The equilibrium adsorption capacity of the nitrobenzene in the sand medium calculated according to the Yoon-Neison theory is exaggerated,particularly in the 8 groups through this experiment,about 2.6-6.3 times.2.According to the breakthrough curves and the adsorption characteristics of sand column,the adsorption process of the nitrobenzene in the sand column is divided into four stages.In the breakthrough experiment,the change of the nitrobenzene adsorption process of the sand column is similar to a breakthrough curve if we see sand columns as a unit.The adsorption began from the beginning,and increased to a maximum at some time,then decreased to 0 as the completion of the breakthrough experiment.3.According to analysis of fitting results used in this experiment,to fit the breakthrough curves only by the breakthrough experiment of nitrobenzene sometimes encountered in sand column desorption which is clearly contray to the facts,but the modified model can response to the objective facts better.In the amendment process,we need determine whether the results of the original model fit the conditions ofâ…°,â…±of 3.3.2 or not.If it does,the amendment is not required;if not,the model needs to be amended.4.In this experiment,concentration in the experimental concentration range has little effect on the penetration model,so we can ignore the effect of concentration to the model.In the same concentration,the equilibrium adsorption capacity of the medium increases with the height of the penetration;the adsorption capacity of fine sand is bigger than the medium sand's.5.According to the results of this study with the previous results,three parameters can obtained from the breakthrough experiment:diffusion coefficient,adsorption coefficient and saturated water content.The equilibrium adsorption capacity,adsorption coefficient and saturated water content is the result of this study.The diffusion coefficients of the fine sand and medium sand are 1.75cm2/min,7.16cm2/min;the dispersions are 1.372cm,0.813cm;the adsorption coefficients are 0.189 and 0.153;and the saturated water content are 42.15% and 40.53%.