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Advisor(s)
Abstract(s)
Besides several toxic heavy metals, electroplating effluents can have in solution different cations and
anions, which may influence heavy metals removal by the biomass. Among them, fluorides are commonly
used in the electroplating industries and thus can be found in the respective wastewaters. In the present
work, the effect of the presence of fluorides in the efficiency of chromium(III), copper(II) and nickel(II)
removal, from an effluent, by heat-inactivated cells of a brewing flocculent strain of Saccharomyces
cerevisiae was evaluated. The presence of fluorides severely decreased (460%) the removal of
chromium(III) by yeast biomass. This effect impaired the effective treatment of the effluent according to
the US Environmental Protection Agency and the Portuguese law; conversely, a higher removal of
copper(II) and nickel(II) was observed. This behaviour can be understood by metal speciation. In the
presence of fluorides, chromium(III) was mainly complexed, becoming unavailable for yeast accumulation;
this effect decreased the efficiency of chromium(III) removal. Thus, in the presence of fluorides, less
chromium(III) is associated with biomass and consequently more yeast binding sites remain available for
the uptake of other metals present in solution. This fact explains the increase of copper(II) and nickel(II)
removal in the presence of fluorides.
Description
Keywords
Bioavailability Bioremediation Biosorption Chemical speciation Heavy metals removal
Citation
Publisher
Taylor & Francis