Samaria-doped ceria nanopowders for heavy metal removal from aqueous solution

In this study, the feasibility and performance of samaria-doped ceria nanopowder (SDC) as an absorbent for Pb(II), Cu(II) and Zn(II) removal from synthetic wastewater is investigated in batch studies. Two commercial SDC nanopowders; SDC-I and SDC-F, are comparatively studied their morphology, crystal structure, specific surface area and pore volume in order to distinguish the effect of above features on the adsorption capability for metal-ion removal. The spherical SDC-F nanopowder is more effective for removal those three metals than SDC-1 nanopowders having a cluster plate-like structure. Among those three metal ions, Pb(II) shows the highest sorption amount on the SDC-F surface. The adsorption parameters for Pb(11) on SDC-F are optimized via variable pH values, metal-ion concentrations, adsorbent dosages, temperatures and contact times. Adsorption capacity of Pb(II) on SDC-F nanopowder is maximum at pH = 5.6. Higher removal ability is found at lower metal-ion concentration but higher adsorbent dosage, temperature and contact time. Kinetic studies reveal that the adsorption of Pb(II) on SDC-F nanopowder follows the pseudo-second-order model. The maximum adsorption capacity of SDC-F for Pb(II) ions calculated by Langmuir isotherm is 23 mg g(-1). Adsorption of Pb(II) on SDC-F is confined by the agglomeration of spherical nanoparticles. The outcome of this study shows that the SDC-F nano particles is possible candidate for removal of Pb(II) ions from wastewater. (C) 2018 Elsevier B.V. All rights reserved.