title: Experimental measurement of proton, Cd, Pb, Sr, and Zn adsorption onto the fungal species Saccharomyces cerevisiae.
abstract: Proton, Cd, Pb, Sr, and Zn adsorption onto the fungal species Saccharomyces cerevisiae were measured in bulk adsorption experiments as a function of time, pH, surface: metal ratio, and ionic strength, and we measured the electrophoretic mobility of the cells as a function of pH. We modeled the acid/base properties of the fungal cell wall by invoking a nonelectrostatic surface complexation model with four discrete surface organic acid functional group types, with average pKa values (with 1 sigma uncertainties) of 3.4 +/- 0.4, 5.0 +/- 0.2, 6.8 +/- 0.4, and 8.9 +/- 0.6. The affinity of the fungal cells for the metal ions follows the following trend: Pb > Zn > Cd > Sr. We used the metal adsorption data to determine site-specific stability constants for the important metal fungal surface complexes. Our results suggest that S. cerevisiae may represent a novel biosorbent for the removal of heavy metal cations from aqueous waste streams.
authors.affiliation: National Centre for Excellence in Physical Chemistry, University of Peshawar, Peshawar, Pakistan.
authors.forename: A
authors.initials: A
authors.lastname: Naeem
authors.forename: J R
authors.initials: JR
authors.lastname: Woertz
authors.forename: J B
authors.initials: JB
authors.lastname: Fein
mesh_terms: D000327:Adsorption; D001673:Biodegradation, Environmental; D002104:Cadmium / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D007854:Lead / Q000737:chemistry; D019216:Metals, Heavy / Q000737:chemistry* / Q000378:metabolism; D011199:Potentiometry; D012441:Saccharomyces cerevisiae / Q000737:chemistry* / Q000378:metabolism; D013324:Strontium / Q000737:chemistry; D013816:Thermodynamics; D014865:Waste Disposal, Fluid / Q000379:methods; D015032:Zinc / Q000737:chemistry
chemical_list: D019216:Metals, Heavy; D002104:Cadmium; D007854:Lead; D015032:Zinc; D013324:Strontium