Li Jiefei, Zhong Zhaoping, Yang Yuxuag, Zhang Shan, Du Haoran, Ren Pengkun
Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing, 210096, China.
Central Plains Environmental Protection Co., Ltd, Zhengzhou, 450000, China.
Environ Sci Pollut Res Int. 2023 Jan;30(2):4309-4322. doi: 10.1007/s11356-022-22509-8. Epub 2022 Aug 15.
Experiment and mechanism studies on the enrichment of Pb, Cd, Zn, As, and Cr by modified kaolin were investigated during MSW (municipal solid waste) pyrolysis at 450 ~ 650 °C. The results showed that γAlOK(micro- and nano-γAlO by hydrothermal method modified kaolin) was relatively selective for the solid phase enrichment of Cr and As, while CaHPK (CaHPO impregnated modified kaolinite) was more advantageous for the adsorption of Pb and Zn, which might be related to the thermal stability of γAlO and the thermal conversion of CaHPO. Compared with the original kaolin, the adsorption and retention capacity of γAlOK for As was improved by 20 ~ 30%. Moreover, the retention rate of modified kaolin for Cd decreased from 66.75 to 30.30% at 450 ~ 650 ℃, and the effect of temperature on the volatilization of Cd was always greater than the active components on the surface of modified kaolin. In the fluidized bed experiment, the physical mixing of different modified kaolin achieves complementary advantages on the retention capacity of heavy metals. In addition, the ∆E between CaPO and PbCl is smaller than that of γAlO at 500 ~ 650 °C, i.e., their electron transfer induction is stronger, and therefore more favorable for electron transfer and stable chemical bond formation.
研究了在450650℃城市固体废弃物（MSW）热解过程中，改性高岭土对铅、镉、锌、砷和铬的富集实验及机理。结果表明，γAlOK（水热法改性高岭土制备的微米和纳米γAlO）对铬和砷的固相富集具有较高的选择性，而CaHPK（磷酸氢钙浸渍改性高岭土）对铅和锌的吸附更具优势，这可能与γAlO的热稳定性和磷酸氢钙的热转化有关。与原高岭土相比，γAlOK对砷的吸附和保留能力提高了2030%。此外，在450650℃时，改性高岭土对镉的保留率从66.75%降至30.30%，温度对镉挥发的影响始终大于改性高岭土表面活性成分的影响。在流化床实验中，不同改性高岭土的物理混合在重金属保留能力上实现了优势互补。此外，在500650℃时，CaPO与PbCl之间的∆E小于γAlO，即它们的电子转移诱导更强，因此更有利于电子转移和稳定化学键的形成。
