Ecke Holger
Division of Waste Science & Technology, Luleå University of Technology, SE-971 87 Luleå, Sweden.
Waste Manag. 2003;23(7):631-40. doi: 10.1016/S0956-053X(03)00095-3.
Waste management is in need of a reliable and economical treatment method for metals in fly ashes from municipal solid waste incineration (MSWI). However, no state-of-the-art technique has gained wide acceptance yet. This paper is a synthesis of five elsewhere published investigations covering a project which aimed to assess the possibilities and limitations of adding carbon dioxide (CO2) to fly ash as a stabilization method. Carbonation factors that were studied are the partial pressure of carbon dioxide (CO2), the addition of water, the temperature, and the reaction time. Laboratory experiments were performed applying methods such as factorial experimental design, thermal analysis, scanning electron microscopy (SEM), X-ray diffraction (XRD), and leaching assays including pHstat titration and sequential extraction. Leaching data were verified and complemented using chemical equilibrium calculations. Data evaluation was performed by means of multivariate statistics such as multiple linear regression, principal component analysis (PCA), and partial least squares (PLS) modeling. It was found that carbonation is a good prospect for a stabilization technique especially with respect to the major pollutants lead (Pb) and zinc (Zn). Their mobility decreased with increasing factor levels. Dominating factors were the partial pressure of CO2 and the reaction time, while temperature and the addition of water were of minor influence. However, the treatment caused a mobilization of cadmium (Cd), requiring further research on possible countermeasures such as metal demobilization through enhanced silicate formation.
垃圾管理需要一种可靠且经济的方法来处理城市固体废物焚烧（MSWI）飞灰中的金属。然而，目前尚无先进技术得到广泛认可。本文综合了其他地方发表的五项调查，这些调查涵盖了一个旨在评估向飞灰中添加二氧化碳（CO₂）作为稳定化方法的可能性和局限性的项目。所研究的碳酸化因素包括二氧化碳（CO₂）的分压、水的添加量、温度和反应时间。通过析因实验设计、热分析、扫描电子显微镜（SEM）、X射线衍射（XRD）以及包括pH计滴定和连续萃取在内的浸出试验等方法进行了实验室实验。利用化学平衡计算对浸出数据进行了验证和补充。通过多元统计方法如多元线性回归、主成分分析（PCA）和偏最小二乘法（PLS）建模进行数据评估。结果发现，碳酸化作为一种稳定化技术具有良好的前景，特别是对于主要污染物铅（Pb）和锌（Zn）而言。它们的迁移率随因素水平的增加而降低。主要因素是CO₂的分压和反应时间，而温度和水的添加量影响较小。然而，该处理导致了镉（Cd）的活化，需要进一步研究可能的对策，如通过增强硅酸盐形成来使金属失活。
