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Comparative mathematical modelling of a green approach for bioaccumulation of cobalt from wastewater

Author:
Mateos, L.M., Villadangos, A.F., Santana, L.K., Pereira, F.J., de la Rubia, A.G., Gil, J.A., Aller, A.J.
Source:
Environmental science and pollution research international 2016 v.23 no.23 pp. 24215-24229
ISSN:
0944-1344
Subject:
Bacillus subtilis, Gram-positive bacteria, aqueous solutions, bioaccumulation, cell walls, cobalt, heavy metals, industrial wastes, industry, mathematical models, microbial biomass, phylogeny, 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.
Agid:
5697151