Study On Adsorption Characteristics Of Engineering Mud And Dewatering Of Waste Slurry

In recent years,with the vigorous development of the urbanization development strategy,the industrial and civil buildings needed to meet people's work and life have been extensively built,and the basic projects play a pivotal role in the construction,especially the bored piles.However,at the same time,the construction of bored piles will produce engineering waste mud.In the eastern coastal areas,due to the deep clay layer in the stratum,the amount of engineering waste mud generated is large,the mud content is high,and it is difficult to handle,which is serious to the urban ecological environment.Threat,so scientific and effective treatment of engineering waste mud is an urgent problem to be solved.The treatment methods of engineering waste mud mainly include curing method and dehydration method.The curing method is to add a curing agent to the waste mud,and convert the mud into a solid engineering material through the action of gelation and ion exchange of materials,and the commonly used curing agent is fly ash,phosphogypsum,etc.,but the action time is long and subject to the site.The factors are large,and the rapid reduction of the engineering waste mud cannot be realized.The dehydration method refers to adding flocculant into the waste mud,and flocculates the particles in the mud into large particles through bridging,electrical neutralization,net trapping,etc.,through free sedimentation.Or mechanical pressure to achieve solid-liquid separation of the mud.The dehydration method is a very effective method for treating waste mud and is widely used in engineering.A large number of engineering practices have shown that the high sludge content of engineering waste mud is difficult to dewater due to the formation of a stable colloid-suspension mixture system,which is essentially the adsorption product of soil particles in the engineering waste mud.Therefore,it is necessary to study the adsorption characteristics of engineering waste mud and study the dehydration method from the adsorption theory.In this paper,the high mud content engineering waste mud based on Chengdu clay is taken as the research object.Based on the adsorption characteristics of Chengdu clay engineering waste slurry,the in-depth study of flocculation method,air pressure method and flocculation-pressure methodare three kinds of dehydration methods.seperate effect.Around the purpose of the research,the work and achievements of this paper mainly include the following:(1)Study engineering mud adsorption and colloidal chemical properties.Through the analysis of the characteristics and composition of the engineering mud,it is determined that the adsorption characteristics of the engineering mud mainly depend on the clay.The crystal structure and hydration of clay minerals were then analyzed and the clay-water adsorption process was analyzed.Finally,the colloidal stability of the engineering mud and how to destroy the stability are analyzed,and the theoretical basis for the dehydration below is made.(2)Study on the adsorption and flocculation characteristics of Chengdu clay engineering waste slurry.For basic tests of water: Chengdu clay and water: sodium bentonite in different proportions,test the adsorption characteristics of Chengdu clay engineering waste slurry,and select water: Chengdu clay: sodium bentonite(100:30:20)The experimental waste slurry samples were subjected to static flocculation test,and the static flocculation effect of different flocculants was compared by the dumping test and particle size after flocculation.(3)Analysis of engineering waste water dehydration method.The principle of flocculation method,air pressure method and flocculation-pressure method are mainly described.Among them,for the air pressure method,the dewatering effect of the Chengdu clay engineering waste slurry was studied.(4)Study the flocculation-pressure dewatering effect of Chengdu clay engineering waste slurry.In this chapter,the flocculation-pressure method dehydration test was carried out on different inorganic flocculants(PAC,PAFC,PFS)and different concentrations of single organic flocculants(APAM,PEO).On this basis,the inorganic polymer polyaluminum chloride(PAC)was compounded with two organic flocculants,and the dewatering effect of the compound flocculant under flocculation-pressure method was analyzed by orthogonal test and range method.Then the dewatering efficiency of single flocculant and complex flocculant under flocculation-air pressure method was compared,and the effect of organic flocculant PEO and APAM on flocculation dehydration was compared,and the principle of net flocculation of two flocculants was analyzed.(5)Study the flocculation-pressure dewatering effect of engineering waste slurry in different regions.Through the above-mentioned formulation and dehydration method,we conducted dehydration test on the same proportion of Ningxia clayengineering waste slurry.At the same time,the dewatering effect of the engineering waste slurry of the clay bored pile in Chongqing Garden Expo Park was studied.According to the test results,the experimental formula and dehydration method studied in this paper have good engineering application effects.This paper has good performance for the formulation and dewatering method developed by solid-liquid separation of Chengdu clay engineering waste slurry.It is not only suitable for engineering waste slurry in Chengdu area,but also suitable for Ningxia loess project waste slurry and Chongqing engineering waste slurry.Dehydration efficiency.The research on engineering mud adsorption and waste slurry dewatering has certain research value and engineering application value for promoting the development of engineering waste mud treatment technology.