The immobilization of potentially toxic elements due to incineration and weathering of bottom ash fines

Qadeer Alam (Corresponding author), Katrin Schollbach, Marco Rijnders, Corrie van Hoek, Sieger van der Laan, H.J.H. Brouwers

Research output: Contribution to journalArticleAcademicpeer-review

10 Citations (Scopus)
1 Downloads (Pure)

Abstract

Incineration bottom ash fines (≤ 125 μm) are known to contain potentially toxic elements (PTEs) and inorganic salts. The most abundant PTEs in the fines were Zn (0.5%), Cu (0.25%), Pb (0.12%), Mn (0.08%) and Cr (0.03%). The systematic quantification of the mineral phases and PTEs associated with them was performed with a multimethod approach using quantitative XRD, phase mapping with PhAse Recognition and Characterization (PARC) software and microprobe analysis. The mineral phases in the fines can be categorized as follows: 1) residual phases (e.g., quartz), 2) incineration phases (e.g., melilitic slag and iron oxides) and 3) quenching/weathering phases (e.g., calcite, ettringite, gypsum, hydrous Fe- and Al-oxides). Among the incineration phases, the melilitic slag was observed to contain Cr, Cu and Zn with 0.02%, 0.13% and 0.19%, respectively. In order of predominance, the weathering phases containing the most PTEs were: calcite < ettringite < hydrous Al-oxides < hydrous Fe-oxides. More than 70% of the phases in the BA fines were formed during incineration and weathering processes that explain the enrichment of PTEs in the smaller particles. During the one-batch leaching test, dissolution of weathering phases, especially ettringite, was observed (total mass loss: 7.2%).

Original languageEnglish
Article number120798
Number of pages9
JournalJournal of Hazardous Materials
Volume379
DOIs
Publication statusPublished - 5 Nov 2019

Keywords

  • Bottom ash
  • Leaching
  • MSWI
  • Potentially toxic elements
  • Weathering

Fingerprint Dive into the research topics of 'The immobilization of potentially toxic elements due to incineration and weathering of bottom ash fines'. Together they form a unique fingerprint.

Cite this