INSTM and Chemistry for Technologies Laboratory, Department of Mechanical and Industrial Engineering, University of Brescia, Via Branze, 38, 25123 Brescia, Italy.
INSTM and Chemistry for Technologies Laboratory, Department of Mechanical and Industrial Engineering, University of Brescia, Via Branze, 38, 25123 Brescia, Italy.
Waste Manag. 2020 Oct;116:147-156. doi: 10.1016/j.wasman.2020.07.031. Epub 2020 Aug 12.
This paper reports a complete characterization of the lowest fractions of bottom ash derived from co-combustion of municipal solid waste with sewage sludge (COBA), with the aim to suggest suitable reuse strategies of this by-product. X-Ray Microanalysis is coupled with mineralogical characterization, based on X-Ray Diffraction and Rietveld refinement, to extract information about COBA crystalline and amorphous phases. The composition of different particle size fractions shows that amount of amorphous increases with the increase of fractions sizes. In particular, the finest COBA size fraction (<300 μm) shows more leachable heavy metals (i.e. Pb, and Zn) compared to the investigated fraction with the highest sizes (1400 µm). On the basis of their composition, lowest particle size fractions show a better hydraulic behavior compared to bottom ash obtained from incineration of only municipal solid waste, suggesting possible attractive COBA applications, as for example, Portland cement substitution. In addition, COBA with size fractions in the range of 1000-1400 μm are proposed to be used to produce glass and ceramic. Finally, due to its high amount of reactive amorphous phase (about 73% for fraction size of 1400 μm) COBA is used, in combination with other by-products (coal fly ash and flue gas desulphurization residues), to stabilize municipal solid waste incinerator fly ash produced at the same incinerator plant, following the azure chemistry principle of use a waste to stabilize another waste.
本文全面描述了源自城市固体废物与污水污泥共燃烧的底灰（COBA）的最低级分，旨在为该副产品的合适再利用策略提供建议。X 射线微分析与矿物学特性相结合，基于 X 射线衍射和 Rietveld 精修，提取 COBA 结晶和无定形相的信息。不同粒径分数的组成表明，无定形物的含量随着分数尺寸的增加而增加。特别是，最细的 COBA 粒径分数（<300μm）比研究的最高粒径分数（1400μm）具有更多可浸出的重金属（即 Pb 和 Zn）。根据其组成，最小粒径分数表现出比仅来自城市固体废物焚烧的底灰更好的水力行为，表明 COBA 可能具有吸引人的应用，例如替代波特兰水泥。此外，提议将粒径在 1000-1400μm 范围内的 COBA 用于生产玻璃和陶瓷。最后，由于其高含量的反应性无定形相（对于 1400μm 的粒径分数约为 73%），COBA 与其他副产品（煤飞灰和烟气脱硫残渣）结合使用，根据使用废物稳定另一种废物的 azure 化学原理，稳定在同一焚烧厂产生的城市固体废物焚烧飞灰。
