title: Valorization of biosorbent obtained from a forestry waste: Competitive adsorption, desorption and transport of Cd, Cu, Ni, Pb and Zn.
abstract: Bark from Pinus pinaster is one of the most abundant forestry wastes in Europe, and among the proposed technologies for its reutilization, the removal of heavy metals from wastewater has been gaining increasing attention. In this work, we have studied the performance of pine bark for heavy metal biosorption on competitive systems. Pb, Cu, Ni, Zn and Cd sorption and desorption at equilibrium were studied in batch experiments, whereas transport was studied in column experiments. Batch experiments were performed adding simultaneously different concentrations (0.08-3.15mM) of two or more metals in solution to pine bark samples. Column experiments were performed with 10mM solutions of two metals or a 5mM solution of the five metals. In general, the results under competitive conditions were different to those obtained in monoelemental experiments. The multi-metal batch experiments showed the adsorption sequence Pb≈Cu>Cd>Zn>Ni for lower metal doses, Pb>Cu>Cd>Zn>Ni for intermediate doses, and Pb>Cu>Cd≈Zn≈Ni for high metal doses. Desorption followed the sequence Pb<Cd<Cu<Zn<Ni for the lowest metal doses, and Pb<Cu<Zn<Cd<Ni for the highest ones. The bi-metal batch experiments indicated that Cu and Pb suffered the highest retention, with high capacity to displace Cd, Ni and Zn from adsorption sites on pine bark. The transport experiments produced comparable results to those obtained in the batch experiments, with pine bark retention capacity following the sequence Pb>Cu>Zn>Cd>Ni. The presence of a second metal affected the transport of all the elements studied except Pb, and confirmed the strong influence of Pb and Cu on the retention of the other metals. These results can help to appropriately design decontamination systems using this forestry waste.
authors.affiliation: Área de Edafoloxía e Química Agrícola, Departamento de Bioloxía Vexetal e Ciencia do Solo, Facultade de Ciencias, Universidade de Vigo, Campus de Ourense, As Lagoas s/n, 32004 Ourense Spain.
authors.forename: Laura
authors.initials: L
authors.lastname: Cutillas-Barreiro
authors.affiliation: Área de Edafoloxía e Química Agrícola, Departamento de Bioloxía Vexetal e Ciencia do Solo, Facultade de Ciencias, Universidade de Vigo, Campus de Ourense, As Lagoas s/n, 32004 Ourense Spain.
authors.forename: Remigio
authors.initials: R
authors.lastname: Paradelo
authors.affiliation: Área de Edafoloxía e Química Agrícola, Departamento de Bioloxía Vexetal e Ciencia do Solo, Facultade de Ciencias, Universidade de Vigo, Campus de Ourense, As Lagoas s/n, 32004 Ourense Spain.
authors.forename: Alba
authors.initials: A
authors.lastname: Igrexas-Soto
authors.affiliation: Departamento de Edafoloxía e Química Agrícola, Universidade de Santiago de Compostela, Escola Politécnica Superior, Campus Universitario s/n, 27002 Lugo Spain.
authors.forename: Avelino
authors.initials: A
authors.lastname: Núñez-Delgado
authors.affiliation: Departamento de Edafoloxía e Química Agrícola, Universidade de Santiago de Compostela, Escola Politécnica Superior, Campus Universitario s/n, 27002 Lugo Spain.
authors.forename: María José
authors.initials: MJ
authors.lastname: Fernández-Sanjurjo
authors.affiliation: Departamento de Edafoloxía e Química Agrícola, Universidade de Santiago de Compostela, Escola Politécnica Superior, Campus Universitario s/n, 27002 Lugo Spain.
authors.forename: Esperanza
authors.initials: E
authors.lastname: Álvarez-Rodriguez
authors.affiliation: Chemical Engineering Department, Faculty of Science, University of Vigo, Campus of Ourense, As Lagoas s/n, 32004 Ourense Spain.
authors.forename: Gil
authors.initials: G
authors.lastname: Garrote
authors.affiliation: Área de Edafoloxía e Química Agrícola, Departamento de Bioloxía Vexetal e Ciencia do Solo, Facultade de Ciencias, Universidade de Vigo, Campus de Ourense, As Lagoas s/n, 32004 Ourense Spain.
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Nóvoa-Muñoz
authors.affiliation: Área de Edafoloxía e Química Agrícola, Departamento de Bioloxía Vexetal e Ciencia do Solo, Facultade de Ciencias, Universidade de Vigo, Campus de Ourense, As Lagoas s/n, 32004 Ourense Spain. Electronic address: mastevez@uvigo.es.
authors.forename: Manuel
authors.initials: M
authors.lastname: Arias-Estévez
mesh_terms: D000327:Adsorption; D001692:Biological Transport; D002104:Cadmium / Q000378:metabolism / Q000493:pharmacokinetics; D003300:Copper / Q000378:metabolism / Q000493:pharmacokinetics; D005060:Europe; D016468:Forestry; D007854:Lead / Q000378:metabolism / Q000493:pharmacokinetics; D019216:Metals, Heavy / Q000032:analysis / Q000378:metabolism* / Q000493:pharmacokinetics; D009532:Nickel / Q000378:metabolism / Q000493:pharmacokinetics; D028223:Pinus / Q000378:metabolism*; D024301:Plant Bark / Q000378:metabolism*; D014866:Waste Products; D015032:Zinc / Q000378:metabolism / Q000493:pharmacokinetics
chemical_list: D019216:Metals, Heavy; D014866:Waste Products; D002104:Cadmium; D007854:Lead; D003300:Copper; D009532:Nickel; D015032:Zinc
keywords: Batch experiments; Biosorbent; Column experiments; Heavy metals; Pine bark; Remediation