BIOSORPTION OF ANTIMONY AND CHROMIUM SPECIES BY SPIRULINA-PLATENSIS AND PHASEOLUS - APPLICATIONS TO BIOEXTRACT ANTIMONY AND CHROMIUM FROM NATURAL AND INDUSTRIAL WATERS

The ability of the two biological substrates, Spirulina platensis (a c yanobacterium) and Phaseolus (a plant-derived material) to accumulate Sb and Cr species (Sb-III, Sb-V, Cr-III and Cr-VI) was evaluated, Diff erent parameters affecting accumulation were tested: pH, temperature, incubation time, amount of biomass and analyte, presence of foreign io ns and the influence of the oxidation state, The experimental data wer e modeled using sorption isotherms and the corresponding sorption coef ficients of each species were calculated for both substrates, S. plate nsis and Phaseolus were suitable for the accumulation of Sb and Cc spe cies over a wide variety of experimental conditions and the accumulati on depended on the oxidation state of the analyte, S, platensis was ap plied to preconcentrate Sb and Cr in river and sea-water samples. The detection limits of the electrothermal atomic absorption spectrometric procedures obtained for Sb in river water (preconcentration factor 4) and sea-water samples (preconcentration factor 40) were 0.9 and 0.09 pg l(-1) respectively, and those for Cr mere 0.1 mu g l(-1) (preconcen tration factor 10) and 0.05 mu g l(-1) (preconcentration factor 20), r espectively. The removal of chromium ions from a leather industrial wa ste water was also examined using this substrate. S. platensis was abl e to remove 97% of Cr from the waste water and therefore proved to be an alternative for the reclamation and remediation of contaminated wat ers. The vegetable substrate Phaseolus, is highly promising for specia tion purposes at low analyte concentrations.