Selective recovery of gold and other metal ions from an algal biomass

• Published in: Environmental science & technology Vol. 20; no. 2; pp. 206 - 208
• Main Authors: Darnall, Dennis W, Greene, Benjamin, Henzl, Michael T, Hosea, J. Michael, McPherson, Robert A, Sneddon, Joseph, Alexander, M. Dale
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 01-02-1986
• Subjects: Applied sciences; Exact sciences and technology; General purification processes; Pollution; Wastewaters; Water treatment and pollution; Elution; Zinc «II» Ions; Algae; Chlorella vulgaris; Chlorophycophyta; Gold III Ions; Desorption; Biomass; Metal; Recovery; Copper «II» Ions; PH; Mercury «II» Ions; Waste water purification; Thallophyta
• ISSN: 0013-936X; 1520-5851
• DOI: 10.1021/es00144a018

The biosorption of chromium, silver, cobalt, nickel, copper, zinc, gold, mercury, lead, tin, uranium, iron, beryllium and aluminium by Chlorella vulgaris was examined. C. vulgaris was either placed directly in contact with the metal ion (batch procedure) or first immobilized in a polyacrylamide matrix (column procedure). Metal ion analysis was by atomic absorption spectrometry or direct current plasma emission spectrometry. The pH dependence of the binding of gold, silver and mercury to the algae was different to the binding of other metals (which were weakly bound at low pH): gold, silver and mercury remained strongly bound at pH 2. Bound gold and mercury could be selectively eluted with mercaptoethanol. An elution scheme for the binding and selective recovery of copper, zinc, gold and mercury from an equimolar mixture is described.