Cementitious materials are commonly used to reinforce the bearing capacity of silty soils. However, there is very little data about how changes in arsenic (As) leaching from silty soils caused by the addition of cementitious materials. Therefore, batch leaching tests were conducted using As-bearing silty soil under different pH conditions. The pH was adjusted by changing the amount of slag cement added or the concentration of sodium hydroxide. This allows us to evaluate the effects of cement on As leaching. In addition, two different additives were applied to reduce As migration. The results show that high concentration of calcium ion (Ca²⁺) in leachates of soil-cement mixture has a significant effect in reducing the mobility of As even under hyperalkaline pH conditions. Arsenic immobilized by Ca²⁺ was observed in two patterns. The first mechanism was the help of Ca²⁺ to reduce the negative electrical potential on the surface of (hydr)oxide minerals under high pH conditions, thereby reducing the mobility of As by adsorption and coagulation of fresh precipitates of Fe and Al hydroxides. The second was the precipitation of calcium carbonate. This precipitate either directly adsorb/co-precipitate As or lower the concentration of strong competing ion, silica, both of which reduced the As mobility. When Ca- or Mg-based additive was added to the silty soil-cement mixture, As concentration in the leachate decreased. These findings are useful in developing sustainable soil-cement reinforcement techniques to avoid contamination.

胶结材料通常用于增强粉质土壤的承载力。但是，关于添加胶凝材料引起的粉质土壤中砷（As）浸出变化的数据很少。因此，使用含砷粉质土壤在不同pH条件下进行了分批浸出试验。通过改变添加的矿渣水泥的量或氢氧化钠的浓度来调节pH。这使我们能够评估水泥对砷浸出的影响。另外，使用了两种不同的添加剂来减少As迁移。结果表明，即使在高碱性pH条件下，土壤-水泥混合物渗滤液中的高浓度钙离子（Ca ²⁺）也具有显着的降低As迁移率的作用。钙固定砷以两种模式观察到²⁺。第一种机制是在高pH条件下，Ca ²⁺有助于减少（氢氧化）氧化物矿物表面的负电势，从而通过吸附和凝结新鲜的Fe和Al氢氧化物沉淀物来降低As的迁移率。第二个是碳酸钙的沉淀。该沉淀物会直接吸附/共沉淀As或降低强竞争离子二氧化硅的浓度，这两者都会降低As的迁移率。当将Ca或Mg基添加剂添加到粉质土壤水泥混合物中时，渗滤液中的As浓度降低。这些发现对开发可持续的土壤水泥加固技术以避免污染很有用。