Leaching of Rare-Earth Elements and Their Adsorption by Using Blue-Green Algae

Abstract

In the present study, REEs were leached from a Vietnamese ore, by using (NH 4 ) 2 SO 4 and REEs were adsorbed from this leachate by bluegreen algae (phormidium). In addition, the biosorption characteristics of phormidium for the adsorption of Nd has been studied.When the concentration of ammonium sulfide was 1%, leaching time was 3 h, and S/L ratio was 0.09, the leaching ratio of Nd was 67.3%. In the adsorption process, when dosage of phormidium was 0.2 kg/L, the contact time was 30 min, and the temperature was 298 K, while pH was kept at the initial value (i.e. pH 5.6), the adsorption density of Nd was 182 mg/kg. These results were similar with the adsorption density of other absorbents, such as: activated carbon, Fe-based absorbent, and calcinated dolomite. Moreover, the equilibrium sorption isotherm of Nd onto phormidium was described by the Langmuir isotherm equation and the pseudo-second-order kinetic model fits the experimental data well.

Cyanobacterial promoted enrichment of rare earth elements europium, samarium and neodymium and intracellular europium particle formation

“…3,[10][11][12][13][14] Among the various microorganisms studied, also cyanobacterial strains proved to be highly capable to biosorb and accumulate dissolved (heavy) metals as well as REE. Kim et al 15 used Phormidium, a genus of lamentous cyanobacteria, to adsorb various REE (La, Pr, Nd, Sm, Gd, Dy) from an ore leachate. With the dead biomass used in this study they found a fast biosorption which occurred for a short time at an early stage.…”

A Potencialidade das Macroalgas na Remoção de Elementos Terras Raras de Águas Contaminadas

“…A biossorção tem vindo a revelar-se como um método eficaz na remoção de elementos tóxicos presentes em soluções, nomeadamente quando estes se encontram em baixas concentrações. Nos últimos anos têm vindo a ser testados diferentes tipos de biossorventes, nomeadamente os constituídos por biomassa de algas, fungos, bactérias, resíduos de plantas e de animais, cascas e diversos outros [8,[11][12][13].…”

Lanthanides and Algae

“…One reason is the risk of reduced availability of resources (China owns more than 95% of natural sources) or their relatively rapid depletion from other sources. Replacement of lanthanides with alternate substances in industrial applications is currently not possible [132,133]. Due to their unique chemical and physical properties and their extensive applications in industrial products, the importance and demand for these elements is constantly increasing [131,134].…”

“…As a biotechnological approach, biosorption is considered to be a more efficient and cheaper alternative to conventional chemical methods of recycling lanthanides [133,145,146]. Various different organic residues of animal or plant origin, including resin, activated charcoal, or biomass of various organisms (algae, fungi, and bacteria), have been shown to adsorb different lanthanides and have been tested as biosorbents [95,98,132,147]. The development of effective biological methods for lanthanide regeneration from these materials was proven in the aerobic, genetically modified bacterium, Caulobacter crescentus [148].…”