Abstract
Municipal solid waste incinerator fly ash (IFA) is categorized as a hazardous waste, which requires proper treatment prior to landfilling due to its high concentrations of toxic elements. This study developed an innovative and cleaner method for stabilization/solidification (S/S) of IFA by the incorporation of supplementary cementitious materials (SCMs) and green stabilizers. Quantitative X-ray diffraction and thermogravimetric analyses indicated that toxic elements in IFA inhibited the cement hydration. Therefore, the single use of cement (10 wt%) was not efficient for the immobilization of toxic elements, especially for Pb. The incorporation of SCMs (20 wt% of binder) such as silica fume facilitated the formation of additional cement hydrates and reduced Pb leachability by 36.3%. The addition of green stabilizers such as potassium dihydrogen phosphate (KDP) and wood waste-derived biochar also improved the immobilization of toxic elements. KDP directly combined with Pb 2+ to form a precipitate of Pb 3 (PO 4 ) 2 whereas biochar promoted the generation of cement hydrates for S/S via the effect of internal curing. The incorporation of silica fume (40 wt%) in the binder was the most effective. Overall, this study demonstrated that the selected green binders can serve as low-carbon and high-efficient material for S/S of hazardous ash residue such as IFA.
Original language | English |
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Pages (from-to) | 335-343 |
Number of pages | 9 |
Journal | Journal of Cleaner Production |
Volume | 222 |
DOIs | |
Publication status | Published - 10 Jun 2019 |
Keywords
- Green/sustainable remediation
- Hazardous waste treatment
- Incinerator ash
- Metal/metalloid leachability
- Waste valorization/recycling
- Wood waste biochar
ASJC Scopus subject areas
- Renewable Energy, Sustainability and the Environment
- General Environmental Science
- Strategy and Management
- Industrial and Manufacturing Engineering