Main content area

Sorption of different metal ions on magnetic nanoparticles and their effect on nanoparticles settlement

Singhal, Pallavi, Pulhani, Vandana, Ali, Sk. Musharaf, Ningthoujam, Raghumani Singh
Environmental nanotechnology, monitoring & management 2019 v.11 pp. 100202
cesium, hydrogen bonding, iron oxides, lanthanum, magnetism, metal ions, nanoparticles, pH, sodium chloride, sorption, strontium
The present work describes the sorption of Cs+, Sr2+, La3+ and Th4+ on Fe3O4 nanoparticles (NPs). The selection of metal ions was done on the basis of different charges to see its effect on sorption. Experiments were carried out at two different pH, 6 and 9 and in presence of NaCl salt to see the effect of these factors on metal ion removal rate. Interestingly no sorption of metal ions were observed at pH ∼ 6 while at pH ∼ 9 only Sr2+ and La3+ ions can be selectively sorbed on NPs surface. Experiments in presence of high concentration of salt suggest that the presence of salt does not have an appreciable effect on sorption suggesting the formation of an inner sphere complex of these metal ions on NPs surface. Sr2+ and La3+ sorption over NPs surface facilitates the enhancement of settlement of NPs. NPs settlement rate was monitored in presence of different metal ions and interestingly was found to vary with metal ions. The results were explained on the basis of DLVO theory, HSAB (hard soft acid base) principle, hydrogen bonding and different charges on metal ions.