title: Multispecies reactive transport modelling of electrokinetic remediation of harbour sediments.
abstract: We implemented a numerical model to simulate transport of multiple species and geochemical reactions occurring during electrokinetic remediation of metal-contaminated porous media. The main phenomena described by the model were: (1) species transport by diffusion, electromigration and electroosmosis, (2) pH-dependent buffering of H+, (3) adsorption of metals onto particle surfaces, (4) aqueous speciation, (5) formation and dissolution of solid precipitates. The model was applied to simulate the electrokinetic extraction of heavy metals (Pb, Zn and Ni) from marine harbour sediments, characterized by a heterogeneous solid matrix, high buffering capacity and aged pollution. A good agreement was found between simulations of pH, electroosmotic flow and experimental results. The predicted residual metal concentrations in the sediment were also close to experimental profiles for all of the investigated metals. Some removal overestimation was observed in the regions close to the anode, possibly due to the significant metal content bound to residual fraction.
authors.affiliation: Department of Energy, Systems, Territory, and Construction Engineering, University of Pisa, Via C.F. Gabba, 22, 56122 Pisa (PI), Italy. Electronic address: m.masi@ing.unipi.it.
authors.forename: Matteo
authors.initials: M
authors.lastname: Masi
authors.affiliation: Department of Chemistry and Industrial Chemistry, University of Pisa, Via Giuseppe Moruzzi, 13, 56124 Pisa (PI), Italy. Electronic address: alessio.ceccarini@unipi.it.
authors.forename: Alessio
authors.initials: A
authors.lastname: Ceccarini
authors.affiliation: Department of Energy, Systems, Territory, and Construction Engineering, University of Pisa, Via C.F. Gabba, 22, 56122 Pisa (PI), Italy. Electronic address: r.iannelli@ing.unipi.it.
authors.forename: Renato
authors.initials: R
authors.lastname: Iannelli
keywords: Buffering capacity; Dredged sediments; Electroremediation; Heavy metals; Numerical model