Effects of anions on the biosorption of microelement cations by macroalga <Emphasis Type="Italic">Enteromorpha prolifera</Emphasis> in single- and multi-metal systems

The results of research on the effects of anions on the biosorption of microelement cations by the edible marine macroalga Enteromorpha prolifera in single- and multi-metal systems are discussed in this paper. It was shown that the maximum biosorption capacity (q _max) in a single-metal system of Co(II) ions decreased in the following sequence: Cl⁻ (46.0 mg g⁻¹) > SO₄ ²⁻ (42.8 mg g⁻¹) > NO₃ ⁻ (41.9 mg g⁻¹). In multi-metal systems, in which the ratios of Cl⁻, NO₃ ⁻, and SO₄ ²⁻ were 0:0:4, 1:1:2, 3:0:1, and 4:0:0, there were clear differences among the biosorption capacities. In all the examined systems (other than the 0:0:4 system), inhibition of the binding of microelement cations by the macroalga was observed. In all the systems, the highest value of q _max was obtained for Cu(II) cations; the value ranged from 31.9 mg g⁻¹ in 0:0:4 (SO₄ ²⁻ only) to 18.2 mg g⁻¹ in 4:0:0 (Cl⁻ only).