Investigations on nickel biosorption and its remobilization

Abstract

Immobilized preparations of the bacteria (Pseudomonas aeruginosa and Rhodopseudomonas BHU strain 1) and the cyanobacterium (Anacystis nidulans) exhibited significant Ni adsorption in the order 91%, 72%, 75%, respectively, within 2 h contact with aqueous NiCl2 (7·05 μg Ni/0·1 mg biomass). The immobilizing agent (Ca-alginate, 1·5%, w/v) absorbed more Ni (43%) than the exopolysaccharide of cyanobacteria, Rivularia sp. (40%) of Aphanothece sp. (30%). Ni remobilization from different adsorbed systems was maximum (84%) for Ca(NO3)2 over NaCl (4·3%) at equimolar concentrations (12 mM, each). Extracts from forest soil (organic C, 2-3%) were more effective in Ni remobilization (22·65%) than similar preparations from garden soil (18%) with organic C in the range of 0·98-1·1%. © 1995.