Mechanics And Infiltration Characteristics Of Sludge Solidification Samples Under The Chemical Solution Corrosion

With the advancement of our country urbanization,the urban water treatment system is developing rapidly,but there are serious in the sewage treatment plant construction in China,"heavy water mud" phenomenon,cause sludge undermining social living environment problems appear constantly.This request of the environmental geotechnical workers take the appropriate method to carry on the reasonable processing waste of urban development,create a better living environment for the society.In order to explore the feasibility of the sludge solidification body as landfill liner material,the sludge solidification body sample is corroded under the condition of chemical solutions and garbage leachate.The triaxial shear properties,microscopic pore structure and the characteristics of penetration of activated sludge solidification body sample are explored through the tests like triaxial shear test,microstructure test,flexible wall penetration test respectively.Results of the sludge solidification body are obtained: shear strength parameters of sample,and pore volume,specific surface area and permeability coefficient of sample.Selection of materials suitable for landfill liner seepage control material.The main conclusions are acquired by the test as mentioned:?1?The influence of acid corrosion on sample shear strength is smaller than alkali and leachate corrosion.After chemical etching solution,sample 3 of shear strength is the largest,sample 7 of shear strength is minimal.When the confining pressure is 200 kpa,the shearing strength of the sample 3 is 833 kpa as shear strength of sample 7 is only 126 kpa.Cohesive force located in the range of 9kpa to 213 kpa,soaking in sulfuric acid solidified body,cohesive force is greater than other conditions;Internal friction angle located in the range of 5° to 31°,internal friction angle of the soaking in distilled water solidification body is the biggest.?2?The adsorption stripping curve of sludge solidification body belongs to the class ? isotherm curve.After corroded in chemical etching solution,the total entrance of the samples arranged from big to small is: specimen,alkali corrosion,acid corrosion leachate corrosion specimens.Acid corrosion sample average minimum aperture,alkali corrosion sample average aperture is the largest;The largest specific surface area of the solidified body is the sample kept in acid corrosion condition,the smaller one is alkali corrosion condition,the leachate condition is the smallest one.The specific surface area of sample 3 which kept in acid condition,leachate condition and alkali condition are 87.035 cm²/g,59.916 cm²/g and 59.916 cm²/g respectively.The average pore size of sample 3 which kept in acid condition,leachate condition and alkali condition are 6.375 nm,7.388 nm and 7.6 nm respectively;The total pore volume of sample 3 which kept in acid condition,leachate condition and alkali condition are 0.138 cm³/g,0.111 cm³/g and 0.118 cm³/g respectively.?3?In acid and alkali condition,the permeability coefficient order of sample 3: alkali > leachate > acid > distilled water.In different ions in the solution,the solution that obtained the biggest permeability coefficient of the sludge solidification body is CaCl₂,the smaller one is MgCl₂ and NaCl is the smallest one,their permeability coefficient were 0.8208×10^-8cm/s,0.6939×10^-8cm/s,0.1035×10^-8cm/s respectively.The permeability coefficient and solution concentration were positively correlated while the solutions are the same but concentrations are different.The permeability of sludge solidification body samples are bellow 1×10^-7cm/s which meets the demand of landfill liner permeability in seepage control system.