Study of calcium(H), copper(H), magnesium(II), and iron(III) interference on Au(III) binding to native hop biomass using ICP-OES

Biosorption of metals from industrial effluents has been studied widely. The economic advantage of scavenging precious metals such as gold has increased the interest in recovery technologies. Hop biomass has been Studied for its capability of uptaking Au(III) ions from aqueous solutions. The interference of Cu(II), Fe(III), Ca(II), and Mg(II) on Au(III) binding to hop biomass was Studied using ICP-OES for metal quantification. Portions of hop biomass were reacted with mixed solutions of Cu(II)-Au(Ill), Fe(III)-Au(III), Cu(II)-Au(III), and Mg(II)-Au(III) at different concentrations. The analysis of the Cu(II)-Au(III) solution showed that Cu(II) ions do not interfere in Au(III) binding at pH 3, 4, and 5. All Fe(III) concentrations seem to have no effect on the Au(III) bindin,g at the pH that was investigated. The presence of Ca(II) increases about 50% the binding of Au(III) at pH 6 and decreases about 25% at pH 2, while the presence of Mg(II) ions increased the Au(III) binding to native hop biomass almost 10% at pH 2 and more than 30% at pH 6.