Biosorption of Cu2+ and Zn2+ from aqueous solutions by dried marine green macroalga Chaetomorpha linum

The biosorption of the heavy metals Cu2+ and Zn2+ by dried marine green macroalga (Chaetomorpha linum) was investigated. The biosorption capacities of the dried alga for copper and zinc were studied at different solution pH values (2-6), different algal particle sizes (100-800 mu m) and different initial metal solution concentrations (0.5-10 mM). An optimum pH value of 5 was found suitable for both metal ions biosorption for both metal ions. At the optimum particle size (100-315 mu m), biosorbent dosage (20 g/l) and initial solution pH (pH 5), the dried alga produced maximum copper and zinc uptakes values (q(max)) of 1.46 and 1.97 mmol/g respectively (according to the Langmuir model). The kinetic data obtained at different initial metal concentrations indicated that the biosorption rate was fast and most of the process was completed within 120 min. This study illustrated an alternative technique for the management of unwanted biological materials using processed algal material. C linum is one of the fast-growing marine algae in the lake of Tunis and could be utilized as a biosorbent for the treatment of Cu2+ and Zn2+ contaminated wastewater streams. (C) 2009 Elsevier Ltd. All rights reserved