Research On The Mechanical Properties And Durability Of Industrial Waste Solidified Urban Sludge

During urbanization,wastewater treatment and reuse equipment are indispensable,which is an important guarantee of production and life.Much of the sludge produced in the wastewater treatment process is not properly treated,while traditional treatment methods have the disadvantages of many consumables and high costs,thus there is an urgent need to explore an efficient and green way of treatment.Based on the Institute of Environment-Friendly Materials and Occupational Health of Anhui University of Science and Technology,Wuhu(ALW2020YF13),this project aims to explore a new technology that can safely control the pollution problem of urban sludge as well as comprehensively treat industrial wastes in the process of vigorous development of heavy industries in China.Three industrial wastes,calcium carbide residue,ground granulated blast slag,and desulfurization gypsum,were selected to configure a new curing agent for curing urban sludge,combining a series of indoor tests,microscopic tests,and theoretical analysis to investigate the strength characteristics,deformation characteristics,durability,and curing mechanism of sludge-cured soil.The main research results are as follows.(1)The strength of the cured sludge soil peaks when the ratio of sludge,calcium carbide residue,ground granulated blast slag and desulfurization gypsum is 100:15:15:5;the strength of the optimum dose of C15G15D5 can reach 1.546 MPa at 28 d,which meets the strength requirements of general fill and is better than the curing effect of cement alone;it also found that there is the strength between the cured sludge soil and the age Power function relationship was also found between the strength and age of cured sludge soil,and the strength prediction equation,by which the strength of sludge cured soil of unknown age can be predicted.(2)The dry and wet cycle tests show that the strength of the specimens with different doping levels increases and then decreases as the number of cycles increases;the higher the doping level,the less the strength characteristics of the specimens are affected and the smaller the range of change in breaking strain,and there is a fitted curve relationship between the strength and breaking strain at different cycle times.(3)XRD and SEM microscopic test structures show that the hydration products are fine particles when the level of curing agent is low,and as the amount of curing agent increases,more hydration products are generated,forming a mesh structure and solid large particles,filling the soil pores,which can effectively improve the ability of cured sludge soil to resist dry and wet effects.(4)Sulfate erosion test shows that,with the increase of erosion time,the specimens immersed in different solutions show an increasing trend,and the higher the concentration of the solution,the more the mass of the specimen increases;during the erosion process,the strength curve of N0 shows a decreasing-growing-decreasing trend,and the strength curves of N2.5 and N5 show a decreasing-growing trend;as the erosion proceeds,the plasticity of the specimen decreases.Figure [65] table [14] reference [116]...