Jun K S, Hwang B G, Shin H S, Won Y S
Department of Environmental Engineering, Yeungnam University, Kyungbuk, Korea.
Water Sci Technol. 2001;44(2-3):399-407.
This paper discusses the development of mixtures with silica fume as a stabilization/solidification agent and binder for industrial wastewater residue containing organic and heavy metal contaminants. The UCS (Unconfined Compressive Strength) gradually increased to 66.7% as the silica fume content increased to 15%. The leaching of TOC and chromium decreased as more OPC was substituted with silica fume. When the mix had 5% silica fume, it retained about 85% TOC, and chromium leached out 0.76 mg-Cr/g-Cr in acidic solution. Also, microstructural studies on the solidified wastes through the scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS) and X-ray diffraction analysis showed that the silica fume caused an inhibition to the ettringite formation which did not contribute to setting, but coated the cement particles and retarded the setting reactions. The results indicated that the incorporation of silica fume into the cement matrix minimized the detrimental effects of organic materials on the cement hydration reaction and contaminant leachability.
本文讨论了以硅灰作为稳定/固化剂和粘结剂，用于含有有机和重金属污染物的工业废水残渣的混合物的开发。随着硅灰含量增加到15%，无侧限抗压强度（UCS）逐渐增加到66.7%。随着更多的普通硅酸盐水泥（OPC）被硅灰替代，总有机碳（TOC）和铬的浸出量减少。当混合物含有5%的硅灰时，它保留了约85%的TOC，并且在酸性溶液中铬的浸出量为0.76 mg-Cr/g-Cr。此外，通过扫描电子显微镜/能谱仪（SEM/EDS）和X射线衍射分析对固化废物进行的微观结构研究表明，硅灰抑制了钙矾石的形成，钙矾石对凝结没有贡献，但包裹了水泥颗粒并延缓了凝结反应。结果表明，将硅灰掺入水泥基体中可将有机材料对水泥水化反应和污染物浸出性的有害影响降至最低。
