Biosorption of cadmium(II) from aqueous solutions by pre-treated biomass of marine alga Durvillaea potatorum

Cadmium(II) adsorption properties of pre-treated biomass (PTB) of marine alga Durvillaea potatorum were investigated. Pre-treatment of the native biomass with calcium chloride and subsequent thermal treatment considerably improved the swelling properties and physical stability of the biomass granules. Batch and column experiments were conducted to determine the adsorption properties of the modified biomass. The adsorption capacity of the biomass strongly depends on equilibrium solution pH. At solution pH of 5, the maximum adsorption capacity of the pre-treated biomass is 1.1 mmol/g. The kinetics of cadmium adsorption was fast with 90% of adsorption taking place within 30 min. The feasibility of using pre-treated biomass granules in a packed bed was also examined. This study demonstrated that the pre-treated biomass of D. potatorum can be used as an efficient biosorbent for the treatment of cadmium bearing waste streams. (C) 1998 Elsevier Science Ltd. All rights reserved.