TY - JOUR
T1 - Geochemical modeling of leaching of Ca, Mg, Al, and Pb from cementitious waste forms
AU - Martens, Evelien
AU - Jacques, Diederik
AU - Van Gerven, T.
AU - Wang, Lian
AU - Mallants, Dirk
N1 - Score = 10
PY - 2010/8
Y1 - 2010/8
N2 - Results from extraction tests on cement–waste samples were simulated with a thermodynamic equilibrium model using a consistent database, to which lead data were added. Subsequent diffusion tests were modeled by means of a 3D diffusive transport model combined with the geochemical model derived from the extraction tests.
Modeling results of the leached major element concentrations for both uncarbonated and (partially) carbonated samples agreed well with the extraction test using the set of pure minerals and solid solutions present in the database. The observed decrease in Ca leaching with increasing carbonation level was qualitatively predicted. Simulations also revealed that Pb leaching is not controlled by dissolution/precipitation only. The addition of the calcite–cerrusite solid solution and adsorption reactions on amorphous Fe- and Al-oxides improved the predictions and are considered to control the Pb leaching during the extractions tests. The dynamic diffusive leaching tests were appropriately modeled for Na, K, Ca and Pb.
AB - Results from extraction tests on cement–waste samples were simulated with a thermodynamic equilibrium model using a consistent database, to which lead data were added. Subsequent diffusion tests were modeled by means of a 3D diffusive transport model combined with the geochemical model derived from the extraction tests.
Modeling results of the leached major element concentrations for both uncarbonated and (partially) carbonated samples agreed well with the extraction test using the set of pure minerals and solid solutions present in the database. The observed decrease in Ca leaching with increasing carbonation level was qualitatively predicted. Simulations also revealed that Pb leaching is not controlled by dissolution/precipitation only. The addition of the calcite–cerrusite solid solution and adsorption reactions on amorphous Fe- and Al-oxides improved the predictions and are considered to control the Pb leaching during the extractions tests. The dynamic diffusive leaching tests were appropriately modeled for Na, K, Ca and Pb.
KW - thermodynamic modelling
KW - lead
KW - ordinary portland cement
KW - waste management
UR - http://ecm.sckcen.be/OTCS/llisapi.dll/open/ezp_106712
UR - http://knowledgecentre.sckcen.be/so2/bibref/7088
U2 - 10.1016/j.cemconres.2010.01.007
DO - 10.1016/j.cemconres.2010.01.007
M3 - Article
SN - 0008-8846
VL - 40
SP - 1298
EP - 1305
JO - Cement and Concrete Research
JF - Cement and Concrete Research
IS - 8
ER -