冻融循环下磷酸镁水泥固化铜污染土的淋滤特性研究

将自制磷酸镁水泥用于铜污染土的固化稳定,研究其淋滤特性和微观结构。以磷酸镁水泥固化铜污染土为研究对象,研究冻融循环条件下磷酸镁水泥掺量、初始铜离子浓度等因素对固化后重金属铜污染土的淋滤特性及固化稳定性的影响。结果表明:冻融循环和磷酸镁水泥掺量会影响磷酸镁水泥固化铜污染土的浸出液中铜离子浓度和上清液pH,随着冻融循环次数和铜离子浓度的减少及水泥掺量的增多,铜离子浓度显著降低;浸出液的pH随冻融循环次数的增多而降低,随磷酸镁水泥水泥掺量的增多而提高,随铜离子浓度的增大而降低。最后与扫描电镜试验结果结合解释了水分迁移对固化机制的影响。

Experimental Study on Leaching Characteristics of Copper Ion-contaminated Soil Cured by Magnesium Phosphate Cementunder Freeze-thaw Cycles

The self-made magnesium phosphate cement was used to solidify and stabilize the heavy metal contaminated soil,study on its leaching characteristics and microstructure. In this paper, the copper ion-contaminated soil was cured by magnesium phosphate cement. The effects of freeze-thaw cycle number, cement content and initial copper ion concentration on the leaching characteristics and stability of the heavy metal copper contaminated soil after solidification were analyzed. The results show that the freeze-thaw cycle and magnesium phosphate cement cem ent content will affect the copper ion concentration and the supernatant pH value in the leachate of the magnesium phosphate cement solidified copper contaminated soil. As the number of freeze-thaw cycles and the concentration of copper ions decrease and the amount of cement increases, the concentration of copper ions decreases significantly. The pH value of the leachate decreases with the increase of the number of freeze-thaw cycles, increases with the increase of MPC cement content, and decreases with the increase of copper ion concentration.The effect of water migration on curing mechanism was explained by scanning electron microscope (SEM).