Bioremoval of toxic metals from aqueous mixtures and recovery of biomass by dispersed-air flotation
In the present paper the solid/liquid separation of suspended, metals-loaded biomass was mainly studied by successfully applying flotation. Industrial non-living biomass samples of different origins have been tried in the laboratory as sorbents of metal ions, with particular emphasis on Streptomyces rimosus, an effective for this purpose biomass. Dispersed-air flotation was used as the harvesting technique downstream, following the biosorption stage. Important parameters of the investigation were the solution pH, the surfactant type and concentration, the applied modification of biomass etc. The reuse and, hence, the recycling of biosorbent, following the appropriate elution, was proved possible. As a result, clean water was produced as underflow of the flotation process, fit for industrial reuse.
Keywords: harvesting, Streptomyces biomass, copper, zinc, nickel, biosorption, bioremoval, toxic metals, aqueous mixtures, biomass recovery, dispersed-air flotation, solid-liquid separation, biosorbent recycling