Experimental Simulation Study of Adsorption of BTEX in the River Filtration System

MA Yan,LI Zhi-ping,LIANG Ke,LIU Ming-zhu(1.School of Resources and Environment,North China Institute of Water Conservancy and Hydroelectric Power,Zhengzhou 450011,China)

River filtration system is a natural purification,which means while the river water passing through the soil and the aquifer material,potential contaminants in the river water are filtered and removed by a series of physical,chemical and biological actions.Based on static adsorption experiments,adsorption kinetic curve and adsorption isotherm of each component of BTEX in three different soil samples were plotted,and some conclusions were obtained as follow.(1)The results of experiments of adsorption dynamics showed that the adsorption reaction balance could be achieved within 48 hours(.2)Adsorption processes in the silt soil and the fine sand were corresponding with Henry model,namely the adsorption capacity was directly proportional to equilibrium concentration of the solution.While adsorption process in the coarse sand accorded with Langmuir model(.3)By comparison of the adsorption isotherm and the soil-water partition coefficient Kd of each BTEX component in different soil samples,it was found that the silt soil and the fine sand possessed relatively higher adsorption capacity than that of the coarse sand.The results also showed that the silt soil and fine sand samples displayed the strongest adsorption capacity to Benzene,to Toluene the second,and that to Ethyl-benzene and M-xylene were much weaker(.4)The retarding factors were relatively high,which showed that the samples of river sediments exhibited quite significant retarding action to BTEX components.BTEX could be removed rather efficiently through adsorption action within a quite high concentration range in the river filtration system.