title: Comparative mathematical modelling of a green approach for bioaccumulation of cobalt from wastewater.
abstract: Cobalt is an essential element, but its wide use in industry generates important environmental and biological problems. The present study explores theoretical and empirical models of a green process for cobalt {Co2+} bioaccumulation from aqueous solutions. Two Gram-positive Bacillus subtilis species, strains CECT 4522 and LMM (the latter a former laboratory isolate from wastewater samples, which was phylogenetically characterized for the present work), were selected among others as the best Co2+accumulation systems. Mathematical models representing kinetic and steady-state conditions for discrete and large amounts of bacterial biomass were expanded. In this way, it was possible to theoretically calculate the amount of Co2+retained on the outer cell wall layer and incorporated inside the cell at any time. Theoretical and empirical hyperbolic-type models were suitable to fit the experimental bioaccumulation data for discrete amounts of bacteria biomass. In addition, kinetic relationships between the amount of Co2+accumulated and the time before (or after) reaching steady state were established for large amounts of bacterial biomass. Other kinetic approaches were also satisfactorily tested. The two Gram-positive bacteria assayed are promising agents for developing heavy metal removal systems from industrial waste.
authors.affiliation: Department of Molecular Biology, Area of Microbiology, Faculty of Biological and Environmental Sciences, University of León, 24071, León, Spain.
authors.forename: L M
authors.initials: LM
authors.lastname: Mateos
authors.affiliation: Department of Molecular Biology, Area of Microbiology, Faculty of Biological and Environmental Sciences, University of León, 24071, León, Spain.
authors.forename: A F
authors.initials: AF
authors.lastname: Villadangos
authors.affiliation: Department of Molecular Biology, Area of Microbiology, Faculty of Biological and Environmental Sciences, University of León, 24071, León, Spain.|Laboratório de Armazenamento de Energia e Tratamento de Efluentes, Instituto de Química, Universidade Federal de Uberlândia-MG, Av. João Naves de Ávila, 2121, CEP 38408-100, Uberlândia, Brazil.
authors.forename: L K
authors.initials: LK
authors.lastname: Santana
authors.affiliation: Department of Applied Chemistry and Physics, Area of Analytical Chemistry, Faculty of Biological and Environmental Sciences, University of León, 24071, León, Spain.
authors.forename: F J
authors.initials: FJ
authors.lastname: Pereira
authors.affiliation: Department of Molecular Biology, Area of Microbiology, Faculty of Biological and Environmental Sciences, University of León, 24071, León, Spain.
authors.forename: A G
authors.initials: AG
authors.lastname: de la Rubia
authors.affiliation: Department of Molecular Biology, Area of Microbiology, Faculty of Biological and Environmental Sciences, University of León, 24071, León, Spain.
authors.forename: J A
authors.initials: JA
authors.lastname: Gil
authors.affiliation: Department of Applied Chemistry and Physics, Area of Analytical Chemistry, Faculty of Biological and Environmental Sciences, University of León, 24071, León, Spain. aj.aller@unileon.es.
authors.forename: A J
authors.initials: AJ
authors.lastname: Aller
mesh_terms: D001673:Biodegradation, Environmental; D018533:Biomass; D003035:Cobalt / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification; D006094:Gram-Positive Bacteria / Q000737:chemistry / Q000378:metabolism; D055772:Green Chemistry Technology / Q000379:methods*; D008962:Models, Theoretical; D062065:Wastewater / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification; D018508:Water Purification
chemical_list: D003035:Cobalt; D062065:Wastewater; D014874:Water Pollutants, Chemical
keywords: Adsorption; Bacillus; Bioremediation; Cobalt bioaccumulation; Green chemistry; Kinetic parameters; Modelling; Pollution