水泥制品中重金属元素的溶出性能及机理分析

Leaching behavior of heavy metals from cement products and mechanism analysis

采用3种工业废渣,配制水泥净浆试件,试验研究了水泥制品中重金属元素的溶出经时变化性能,并对溶出机理进行了分析。结果表明,重金属的溶出主要发生在浸渍早期(14 d),而后趋于平缓,21 d后溶出量极其微小;工业废渣中重金属的含量会在很大程度上影响其总溶出量。重金属离子在粉煤灰水泥制品中的扩散速率排序为Zn>Pb>Cu≈Cr>As>Cd;在矿渣水泥制品中的扩散速率排序为Cu>Zn>Pb>Cr>Cd>As;在炉渣水泥制品中的扩散速率排序为Zn>Pb>Cu>As>Cr>Cd。重金属离子的溶出机制主要受到水泥水化产物溶解度与重金属扩散速率的耦合影响。

Three kinds of industrial wastes were used to make the cement paste specimens.Leaching behavior of heavy metals from the cement products was experimentally researched.The leaching mechanism was also analyzed.Results show that the leaching of heavy metals concentrates at the early age(14 d),and decreases afterwards.The leaching becomes minute,even undetected after 21 d.The content of heavy metals in industrial wastes greatly influences the total leaching of heavy metals.The diffusion rates of heavy metal ions in fly ash cement products are Zn>Pb>Cu≈Cr>As>Cd.The diffusionrates of heavymetal ions inslagcement products areCu>Zn>Pb>Cr>Cd>As.The diffusion rates of heavymetal ions inmunicipal solidwaste incineration flyash cement products are Zn>Pb>Cu>As>Cr>Cd.The leachingmechanismof heavymetals ismainlyinfluencedbythe couplingeffects of thesolubilityof cement hydrationproducts andthediffusionrateof heavymetals.