Department of Chemical Engineering, Lakehead University, Ontario, Canada.
J Environ Manage. 2012 Jun 30;101:59-67. doi: 10.1016/j.jenvman.2012.01.029. Epub 2012 Mar 7.
The effects of accelerated carbonation on the compressive strength and leachability of fly ash-based geopolymer and ordinary portland cement (OPC) doped with Cd(II), Cr(III), Cr(VI), Cu(II), Pb(II) or Zn(II) salts were investigated. Cement was effective at immobilizing Cd, Cr(III), Cu, Pb and Zn under both the Synthetic Precipitation Leaching Procedure (SPLP) and the Toxicity Characteristic Leaching Procedure (TCLP), but ineffective for retaining Cr(VI). Carbonated cement maintained its ability to immobilize Cd, Cr(III), Pb and Zn, but, under acidic TCLP conditions, was much worse at retaining Cu. Geopolymer was effective at immobilizing Cr(III) and Cu, and, to a lesser degree, Cd, Pb and Zn in SPLP leaching tests. Only Cr(III) was immobilized under comparatively acidic TCLP testing conditions. Carbonation did not change the metal retention capacity of the geopolymer matrix. Metal doping caused compressive strengths of both geopolymer and cement to decrease. Carbonation increased the compressive strength of cement, but decreased that of the geopolymer. Geochemical equilibrium modeling provided insight on the mechanisms of metal immobilization.
研究了加速碳酸化对掺 Cd(II)、Cr(III)、Cr(VI)、Cu(II)、Pb(II)或 Zn(II)盐的粉煤灰基地质聚合物和普通波特兰水泥（OPC）的抗压强度和浸出率的影响。水泥在合成沉淀浸出程序（SPLP）和毒性特征浸出程序（TCLP）下对 Cd、Cr(III)、Cu、Pb 和 Zn 的固定都很有效，但对 Cr(VI)无效。碳酸化水泥保持了固定 Cd、Cr(III)、Pb 和 Zn 的能力，但在酸性 TCLP 条件下，固定 Cu 的能力要差得多。地质聚合物在 SPLP 浸出试验中有效固定 Cr(III)和 Cu，并且在较小程度上固定 Cd、Pb 和 Zn。只有 Cr(III)在相对酸性的 TCLP 测试条件下被固定。碳酸化不会改变地质聚合物基质的金属保留能力。金属掺杂导致地质聚合物和水泥的抗压强度降低。碳酸化增加了水泥的抗压强度，但降低了地质聚合物的抗压强度。地球化学平衡模拟提供了对金属固定机制的深入了解。
