PHREEQC modelling of leaching of major elements and heavy metals from cementitious waste forms

Evelien Martens, Diederik Jacques, Tom Van Gerven, Lian Wang, Dirk Mallants

Research outputpeer-review

Abstract

In this study, Ca, Mg, Al, and Pb concentrations leached from uncarbonated and carbonated ordinary Portland cement - dried waste incinerator bottom ash samples during single extraction tests (EN12457 test) at a pH from 1 to 12, were modelled using the geochemical code PHREEQC. A good agreement was found between modelling results and experiments in terms of leached concentrations for Ca, Mg, and Al by defining a single set of pure mineralogical phases for both the uncarbonated and carbonated (three levels) samples. The model also predicted well the observed decrease in Ca leaching with increasing carbonation. Modelling results further revealed that leaching of Pb is not controlled by dissolution/precipitation of pure Pb containing minerals only (carbonates and (hydr)oxides). The addition of solid solutions (calcite-cerrusite and gibbsite-ferrihydrite-litharge solid solutions) and adsorption reactions on amorphous Fe- and Al-oxides improved the model representation of the experimentally observed amphoteric leaching profile of Pb from the cementitious material.

Original languageEnglish
Title of host publicationMaterials Research Society Symposium Proceedings
Subtitle of host publicationScientific Basis for Nuclear Waste Management XXXI
Place of PublicationWarrendale, United States
PublisherMRS - Materials Research Society
Pages475-482
Number of pages8
ISBN (Print)9781605110790
DOIs
StatePublished - Dec 2008
EventMRS 2007 - Materials Research Society - UK: 31st International Symposium on the Scientific Basis for Nuclear Waste Management - Materials Research Society, Sheffield
Duration: 16 Sep 200721 Sep 2007

Publication series

NameMaterials Research Society Symposium Proceedings
Volume1107
ISSN (Print)0272-9172

Conference

ConferenceMRS 2007 - Materials Research Society - UK
Country/TerritoryUnited Kingdom
CitySheffield
Period2007-09-162007-09-21

ASJC Scopus subject areas

  • General Materials Science
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

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