The ability of Pseudomonas aeruginosa to adsorb selectively La{sup}3+, Eu{sup}3+, and Yb{sup}3+from aqueous solution was investigated. The lanthanide biosorption equilibrium obeyed the Brunauer-Emmett-TeIler isotherm model, indicating multilayeradsorption. Determined levels of maximum adsorption capacities were 397μmol/g for lanthanum, 290μmol/g for europium and 326μmol/g for ytterbium (±10). The results indicated that there were about 100 preferential sites for lanthanum per g of drybiomass. Experiments with mixed-cation solutions showed that the sequence of preferential biosorption was Eu{sup}3+ = Yb{sup}3+ La{sup}3+. Biomasses dried at 37 and 70℃ showed the same selective behavior as wet biomass. Inert microbial biomass dried at37250L鎍ppeared to be the most efficient form for experimental use. The uptake of lanthanide by P. aeruginosa cells was not affected by the presence of sodium, potassium, calcium, chloride, sulfate and nitrate ions. Aluminum was a strong inhibitor oflanthanide ions biosorption. 87 of the total A1{sup}3+ was removed from the 3 mM solution, whereas only 8, 20 and 3 of the total La{sup}3+, Eu{sup}3+, and Yb{sup}3+, respectively, were sorbed from 3 mM solutions. The results suggested that cells ofPseudomonas aeruginosa may find promising applications for removal and separation of lanthanide ions from aqueous effluents.
展开▼
