Sustainable stabilization/solidification of municipal solid waste incinerator fly ash by incorporation of green materials

Liang Chen, Lei Wang, Dong Wan Cho, Daniel C.W. Tsang, Lizhi Tong, Yaoyu Zhou, Jian Yang, Qing Hu, Chi Sun Poon

Research output: Journal article publicationJournal articleAcademic researchpeer-review

77 Citations (Scopus)

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 languageEnglish
Pages (from-to)335-343
Number of pages9
JournalJournal of Cleaner Production
Volume222
DOIs
Publication statusPublished - 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
  • Environmental Science(all)
  • Strategy and Management
  • Industrial and Manufacturing Engineering

Cite this