A comparative study on heavy metal biosorption characteristics of some algae

The biosorption of copper(II), nickel(II) and chromium(VI) from aqueous sol utions on dried (Chlorella vulgaris, Scenedesmus obliquus and Synechocystis sp.) algae were tested under laboratory conditions as a function of pH, in itial metal ion and biomass concentrations. Optimum adsorption pH values of copper(II), nickel(II) and chromium(VI) were determined as 5.0, 4.5 and 2. 0. respectively, for all three algae. At the optimal conditions, metal ion uptake increased with initial metal ion concentration up to 250 mg l(-1). E xperimental results also showed the influence of the alga concentration on the metal uptake for all the species. Both the Freundlich and Langmuir adso rption models were suitable for describing the short-term biosorption of co pper(IT), nickel(II) and chromium(VI) by all the algal species. (C) 1999 El sevier Science Ltd. All rights reserved.