Speciation of Cu/Zn/Pb in bottom and fly ash upon different steam washing condition

Municipal solid waste incineration (MSWI) is a widespread technology for MSW treatment, but one of its drawbacks is the production of solid residues: bottom ash (BA) and fly ash (FA). They are characterized by high amounts of chlorides and leachable heavy metals, which limit their potential recycle as secondary raw materials (SRM). In this light, we propose to investigate the speciation of Cu, Zn and Pb, which affects their behaviour as leachable species. Such heavy metals represent some of the commonest source of pollution. We aim to exploit XAS, especially in the XANES region, to get insight into Cu/Zn/Pb speciation, using suitable reference minerals. All this is to understand why a novel pre-treatment, i.e. steam washing, is effective in reducing the release of these metals, and to design further developments. The scientific issue of the present investigation is a contribution to valorize such materials towards a general enhancement of the principle of sustainability of our society.

城市生活垃圾焚烧（Municipal solid waste incineration，MSWI）是当前应用广泛的城市生活垃圾（Municipal solid waste，MSW）处理技术，但其固有弊端之一是会产生两类固体残渣：底灰（bottom ash，BA）与飞灰（fly ash，FA）。这类残渣富含氯化物与可浸出重金属，这一特性极大限制了其作为二次原材料（secondary raw materials，SRM）的资源化利用潜力。有鉴于此，本研究拟探究铜（Cu）、锌（Zn）与铅（Pb）的赋存形态——该形态直接影响这些重金属作为可浸出组分的环境行为。此类重金属是最常见的污染源之一。本研究计划借助X射线吸收光谱（XAS），尤其是其X射线吸收近边结构（XANES）区域的谱学信息，并结合合适的参考矿物，以深入解析铜、锌、铅的赋存形态。上述研究旨在阐明新型预处理工艺——蒸汽洗涤——何以能有效降低上述重金属的浸出释放量，并为后续工艺优化与技术开发提供理论依据。本研究的科学意义在于，为此类固体焚烧残渣的高值化利用提供支撑，助力全社会可持续发展理念的深化与落地。