School of Environmental Science and Engineering, Huazhong University of Science and Technology (HUST), 1037 Luoyu Road, Wuhan, Hubei 430074, China.
School of Environmental Science and Engineering, Huazhong University of Science and Technology (HUST), 1037 Luoyu Road, Wuhan, Hubei 430074, China.
J Hazard Mater. 2016 Nov 15;318:70-78. doi: 10.1016/j.jhazmat.2016.06.042. Epub 2016 Jun 22.
In this research, Bayer red mud (RM) was pretreated through alkali-thermal activation process, and prepared as an one-part geopolymer precursor, which could be used as geopolymeric solidification/stabilization (S/S) reagent for municipal solid waste incineration fly ash (MSWI FA). Compressive strength test, modified TCLP leaching test and sequential extraction test were conducted to evaluate the effectiveness of the RM-based geopolymeric S/S reagent. The results show that the S/S effects for heavy metals of RM-based geopolymer exhibit the following order: Pb>Cu>Zn>Cr. Most of the Zn, Pb and Cu in the MSWI FA transform from the leachable fractions into the inactive fractions difficult or unavailable to leach out. In the geopolymeric S/S solid, the active aluminosilicates in MSWI FA are dissolved in the alkaline environment formed by pretreated RM and then participate in the geopolymerization, which increases the SiO2/Al2O3 ratio and enhances the structural stability of geopolymeric S/S solid. MSWI FA offsets the strength deterioration of RM based one-part geopolymer and improves the immobilization efficiency for heavy metals in the geopolymer structure.
在这项研究中，拜耳赤泥（RM）经过碱热活化预处理，用作单组分地质聚合物前体，可作为城市固体废物焚烧飞灰（MSWI FA）的地质聚合固化/稳定化（S/S）试剂。通过抗压强度试验、改良TCLP 浸出试验和顺序提取试验评价了 RM 基地质聚合物 S/S 试剂的有效性。结果表明，RM 基地质聚合物对重金属的 S/S 效果为 Pb>Cu>Zn>Cr。MSWI FA 中的大部分 Zn、Pb 和 Cu 从可浸出部分转化为难浸出或不可浸出的非活性部分。在地质聚合 S/S 固体中，MSWI FA 中的活性硅铝酸盐溶解在由预处理 RM 形成的碱性环境中，然后参与地质聚合反应，从而提高了 SiO2/Al2O3 比，增强了地质聚合 S/S 固体的结构稳定性。MSWI FA 抵消了 RM 基单组分地质聚合物强度降低的影响，并提高了重金属在地质聚合物结构中的固定效率。
