Geopolymers are new cementitious materials, which can effectively solidify/stabilize heavy metal ions. Fly ash is an industrial waste from the coal-consumed power plant. With thermal power projects continuously building in the world and the emissions and accumulation quantities of fly ash are increasing yearly. At the same time, with the development of modern industry, waste and waste water containing heavy metals are continuously discharged, so that heavy metal pollution has been the very serious world environmental problems. Aiming at the problem of fly ash and heavy metal pollution, this study referred to solidification/stabilization (S/S) of Pb (II), Cd (II), Mn (II) and Cr (III) in fly ash based geopolymers prepared using composite activator of sodium silicate and sodium hydroxide. The solidification (S/S) results had been explained by means of the leaching and compressive strength of the solidification (S/S) geopolymers (solidified bodies) acquired. The analysis was performed through chemical analysis, X-ray Diffraction (XRD), Fourier Transform Infrared Spectrometer (FTIR), Scanning Electron Microscope (SEM), Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES) and compressive strength tests. The results indicated that heavy metal ions could be effectively solidified in fly ash based geopolymers with a replacement of safe metal ions like Na (I) and Ca (II). Heavy metal ions had different effects on the compressive strength of geopolymers. (1.5 wt%) Pb (II) was beneficial to improve the compressive strength of geopolymers, and reached 49.34 MPa at 28 d. The XRD patterns indicated an amorphous structure and zeolite-like structure of aluminosilicate. The FTIR patterns study suggested changes of the Si-O-T (T = Si or Al) peak in the geopolymers. The SEM analysis revealed almost condensed homogenous surface of geopolymers. ICP-AES results showed that the geopolymer showed a high degree of solidification (S/S) of the heavy metal ions; in all samples, the solidification rates reached 99.9%. The mechanism of heavy metal ions being solidified was the interaction of physical fixation, adsorption and ion exchange. Finally, the pilot-scale test can achieve the same result on the basis of this study and made preparations for the future of industrialization.

地聚合物是新型的胶结材料，可以有效地固化/稳定重金属离子。粉煤灰是燃煤电厂的工业废物。随着世界范围内火电项目的不断建设，粉煤灰的排放量和累积量逐年增加。同时，随着现代工业的发展，废水和含重金属的废水不断排放，重金属污染已成为世界上非常严重的环境问题。针对粉煤灰和重金属污染的问题，本研究涉及在制备的粉煤灰基地质聚合物中Pb（II），Cd（II），Mn（II）和Cr（III）的固化/稳定化（S / S）使用硅酸钠和氢氧化钠的复合活化剂。固化（S / S）结果已通过获得的固化（S / S）地质聚合物（固化体）的浸出和抗压强度进行了解释。通过化学分析，X射线衍射（XRD），傅立叶变换红外光谱仪（FTIR），扫描电子显微镜（SEM），电感耦合等离子体原子发射光谱法（ICP-AES）和抗压强度测试进行了分析。结果表明，重金属离子可以有效地固化在粉煤灰基地质聚合物中，并替代安全金属离子，例如Na（I）和Ca（II）。重金属离子对地质聚合物的抗压强度有不同的影响。（1.5 wt％）Pb（II）有利于提高地质聚合物的抗压强度，并在28 d时达到49.34 MPa。XRD图谱表明硅铝酸盐具有无定形结构和类似沸石的结构。FTIR模式研究表明地质聚合物中Si-OT（T = Si或Al）峰的变化。SEM分析表明，地质聚合物的表面几乎是均匀凝结的。ICP-AES结果表明，地质聚合物对重金属离子具有较高的固化度（S / S）；在所有样品中，固化率均达到99.9％。重金属离子的固化机理是物理固定，吸附和离子交换的相互作用。最后，在本研究的基础上，中试能达到相同的结果，为工业化的未来做好了准备。SEM分析表明，地质聚合物的表面几乎是均匀凝结的。ICP-AES结果表明，地质聚合物对重金属离子具有较高的固化度（S / S）；在所有样品中，固化率均达到99.9％。重金属离子的固化机理是物理固定，吸附和离子交换的相互作用。最后，在本研究的基础上，中试能达到相同的结果，为工业化的未来做好了准备。SEM分析表明，地质聚合物的表面几乎是均匀凝结的。ICP-AES结果表明，地质聚合物对重金属离子具有较高的固化度（S / S）；在所有样品中，固化率均达到99.9％。重金属离子的固化机理是物理固定，吸附和离子交换的相互作用。最后，在本研究的基础上，中试能达到相同的结果，为工业化的未来做好了准备。吸附和离子交换。最后，在本研究的基础上，中试能达到相同的结果，为工业化的未来做好了准备。吸附和离子交换。最后，在本研究的基础上，中试能达到相同的结果，为工业化的未来做好了准备。