Keywords: Staphylococcus xylosus, Staphylococcus auricularis, Bacillus cohnil, fungus, gram-negative, gram-positive, microorganisms, biomass, hydrophobicity, biosorptive flotation, metal ion removal, adsorption, clean effluent, contact angle, surface tension, zeta-potential
Hydrophobicity in biosorptive flotation for metal ion removal
Several biological systems are known to explore the presence of micro-organisms and their ability to adsorb/bind toxic metals from liquid or solid wastes, a procedure termed biosorption or bioaccumulation. The mechanism of this process is often based on hydrophobicity. This physical-surface property is also the main parameter which, for this reason, should be investigated, for the specification of satisfactory conditions to achieve an effective flotation, which is applied as an alternative method of solid-liquid separation of metal-laden biomass, aiming to produce a clean effluent, suitable either for disposal or for reuse. In the present paper, measurements of contact angle, surface tension and zeta-potential (under similar conditions) of the biological systems of interest are reported.