ISSN:
1573-5176
Keywords:
cadmium adsorption
;
Ectocarpus siliculosus
;
growth conditions
;
adsorption parameters
;
regeneration
;
electron microscopy
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Non-living, freeze-dried material of the brown algaEctocarpus siliculosus (Phaeophyceae) demonstrated high equilibrium uptake of Cd from aqueous solutions (Fehrmann & Pohl, 1993). The alga was grown in 250-L photobioreactors under various growth conditions (light, salinity and nutrient concentrations) in order to obtain larger quantities of biomass and to improve its Cd adsorption capacity. To derive further knowledge on the biosorbant phenomenon different adsorption parameters such as pH for the sorption process and kinetics of Cd adsorption were tested. The maximum adsorption capacity of the freeze-dried biomass exceeded 41 mg Cd per g biomass. After repeated addition of low Cd concentrations the maximum adsorption capacity was lower (31.4 mg Cd per g biomass). In comparison with other adsorbing materials (activated carbon, silica gel, siliceous earth)E. siliculosus showed significantly higher adsorption capacity. Desorption of deposited Cd with 0.1 M HCl resulted in no changes of the adsorption capacity through five subsequent adsorption-/desorption-cycles. Hence, driedE. siliculosus appears to be an efficient material for the elimination of Cd from industrial waste water. Transmission electron microscopic investigations showed an electron dense area in the outer surface layers of the cell wall after Cd adsorption indicating the most likely location of Cd fixation.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02182402
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