Study On Soil Pollution Properties By Cement Soildification In Wenzhou

By the rapid development of industrialization and urbanization,it becomes a serious problem of environmental pollution which causes a huge negative influence on our daily life,and it also becomes the focus researched by the experts and scholars.Curing stability method is widely used because it is simple,economical and effective in repairing contaminated soil foundation.In this paper,the soil pollution caused by common industry in Wenzhou is taken as an example,and the research on cement solidification of heavy metals,salts and organic pollutants is carried out.Through the laboratory experiment and micro structure analysis of the system,this paper discusses the cement solidified soil pollution in different cement dosage,curing age,the change of the concentration of pollutants,and other conditions.At the same time,a comparison was done under the pollution by three different types of cement solidified soil and the curing effect of microscopic characteristics.The conclusions are shown as following:(1)The unconfined compressive strength of several cement solidified soil pollution was studied.It was that the strength of pollution soil mixed with Pb(NO3)2 with the increase of cement content,age,is bigger than that without adding pollutant.The unconfined compressive strength showed a trend of decrease with the increase of concentration of Pb(NO3)2.The reduction of amplitude is larger,the strength is higher.The unconfined compressive strength of cement solidified oil pollution soil increased more obviously than that contained Pb(NO3)2 contaminated soil with the increase of cement content and ages.With the increase of oil content,unconfined compressive strength reduces quickly before a stably slow.The unconfined compressive strength and cement solidification pollution-free soil are similar under the influence of NaCl with the curing age increasing.When cement content is low,it is relatively complex,firstly increased and then decreased along with the change of NaCl content.(2)The study of cohesion and friction angle about cement solidified Pb(NO3)2,oil and NaCl pollution soil varies with the change of influencing factors.Cement curing pollution by three kinds of soil cohesion with the change of cement content and curing age is similar in unconfined compressive strength,but it is different with each other.The internal friction angle is bigger with the increase of cement content and curing age,the increasing amplitude is smaller.As the pollutant concentration changed,cohesion and internal friction angle is relative complex,i.e.the decrease trend.With the increase of concentration of Pb(NO3)2,internal friction angle has a lower after improved the phenomenon firstly,and made a trend of decrease finally.(3)With different dosage of cement,curing age and the concentration of pollutants Pb(NO3)2,leaching characteristics of contaminated soil were studied.It found.leaching liquid of lead ion concentration in the use of cement solidified after gradually reduce.The increase of the curing age can also made Pb(NO3)2 reduced in the leaching liquid concentration,the fluid of the leach Pb(NO3)2 concentration along with the change of initial Pb(NO3)2 concentration change is most obvious.(4)Analyze the different cement dosage,curing age and concentrations of pollutants in different microstructure characteristics of the cement stabilized soil using scanning electron microscopy(SEM).In cement solidified soil pollution,hydration products decreased significantly,pore greaten,structural variation compared with the non-mixed with cement stabilized soil pollutants.The cementation of cement stabilized soil is getting worse and worse with the increase of concentration of pollutants,which was most evident when mixed with oil.