Research Of Acid-resistance Of Magnesium Phosphate Cement Stabilized Zinc-heavy Metal Contaminated Soils Under The Acid Rain Environment

The research aims to investigate the mechanism and properties of magnesium phosphate cement（MPC）stabilized/solidified heavy metal contaminated soils under the acid rain environment with adding waterglass as a comparative study,which was studied by laboratory tests combining theoretical analysis such as microscopic theory.The research focuses on the strength characteristics the stress-strain characteristics,leaching characteristics,microstructure,and discusseing the curing mechanism of MPC curing zinc contaminated soil and the erosion mechanism of acid rain and acid-resistance mechanism with waterglass.The major research is as follows:The characteristics of unconfined compressive strength（UCS）and the variation of stress-strain of cement solidified contaminated soil under acid rain erosion are studied based on the laboratory tests.The effects of different curing agent types（different M/P）,initial pH value of simulated acid rain,waterglass,and heavy metal addition on unconfined compressive strength and uniaxial stress-strain behavior of solidified heavy metal contaminated soil are studied.The effect of acid rain on the corrosion of zinc phosphate contaminated soil by magnesium phosphate cement is studied by semi-dynamic leaching test.The leaching characteristics of cement-stabilized soil under acid rain are studied.The initial pH,leaching time,curing agent type,and the mass of waterglass on the leaching characteristics of Zn²⁺,pH value and conductivity in leach leachate of the sample are studied.The leaching mechanism of Zn²⁺ and its curing mechanism were analyzed.The relationship between the initial pH value of simulated acid rain,the content of water glass and the concentration of Zn²⁺ in leaching leachate is studied.The XRD and SEM are used to characterize the transformation and microstructure of the solidified zinc phosphate contaminated soils under the acid rain erosive environment,respectively.The effects of acid rain on the solidification of heavy metal contaminated soil and the solidification of heavy metals by cement are summarized.The effects of acid rain on the formation of microstructures and the microstructure of solidified soils are compared with the types of hardeners,the initial pH value of simulated acid rain,the addition of heavy metals and the content of water glass.The effect of water glass content on the acid resistance of zinc phosphate contaminated soil by magnesium phosphate cement is discussed.