Abstract
Herein, this paper describes the synthesis of sodium carboxymethyl cellulose (CMC)/iron oxides/multiwalled carbon nanotubes (MMWCNTs) composites (denoted as CMC/MMWCNTs) by a plasma technique and their application to the decontamination of europium ions from aqueous solutions under controlled laboratory conditions. Batch experiments were conducted to understand the interaction mechanism of europium ion sorption onto the surface of CMC/MMWCNTs nanoparticles and to evaluate the application prospects of CMC/MMWCNTs in the field of pollution remediation. The adsorption capacity of Eu(iii) on CMC/MMWCNTs was greater than that of major adsorbents, illustrating that the conjugated CMC could increase the sorption capacity of CMC/MMWCNTs nanoparticles toward Eu(iii) ions through providing multiple hydroxyl and carboxyl functional groups. The mutual interaction of Eu(iii) ion immobilization on CMC/MMWCNTs was contributed to by outer-sphere surface complexation at low pH values, but inner-sphere surface complexation was the dominant interactional mechanism at high pH values. The experimental findings herein demonstrate that CMC/MMWCNTs composites can be highly effective adsorbents for the immobilization of Eu(iii) ions or other trivalent actinide/lanthanide ions from large volumes of aqueous solution.