title: Ionic strength effects in biosorption of metals by marine algae.
abstract: Biosorption, the passive accumulation of metals by biomass, can be used as a cost-effective process for the treatment of metal polluted industrial effluents. The green alga Ulva fascia and the brown seaweeds Sargassum hemiphyllum, Petalonia fascia, and Colpomenia sinuosa were characterized in terms of their number of binding sites, their charge density and intrinsic proton binding constant (pKa) using pH titrations at different ionic strengths. The determined number of binding sites decreased in the order Petalonia > or = Sargassum > Colpomenia > Ulva. Due to their high number of binding sites Sargassum and Petalonia are most promising for biosorption applications. The decrease of proton binding with increasing ionic strength and pH as well as the increase of Cu and Ni binding with increasing pH and decreasing ionic strength could be described by the Donnan model in conjunction with an ion exchange biosorption isotherm.
authors.affiliation: Department of Biology, Institute for Natural Resources and Waste Management, Hong Kong Baptist University, Kowloon Tong, Hong Kong SAR, People's Republic of China.
authors.forename: S
authors.initials: S
authors.lastname: Schiewer
authors.forename: M H
authors.initials: MH
authors.lastname: Wong
mesh_terms: D000042:Absorption; D001665:Binding Sites; D018533:Biomass; D056890:Eukaryota / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D019216:Metals, Heavy / Q000493:pharmacokinetics*; D011522:Protons; D014018:Tissue Distribution; D014865:Waste Disposal, Fluid / Q000379:methods; D014874:Water Pollutants, Chemical / Q000493:pharmacokinetics*
chemical_list: D019216:Metals, Heavy; D011522:Protons; D014874:Water Pollutants, Chemical