Removal of Cu(II) from aqueous solutions by tartaric acid modified multi-walled carbon nanotubes

Take full advantage of the high adsorption capability of tartaric acid (TA) and high stability of multi-walled carbon nanotubes (MWCNTs) in organic/inorganic solvents, TA modified MWCNT (MWCNT-TA) was prepared and its adsorption properties for bivalent copper ion [Cu(II)] were studied. The MWCNT-TA composites were confirmed by Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, and high-resolution transmission electron microscopy (HRTEM). And the surface area of MWCNT-TA was determined by the Brunauer-Emmett-Teller (BET) method. The removal capacity of MWCNT-TA for Cu(II) was further investigated. In order to optimize the adsorption conditions, batch adsorption experiments were performed, and some factors that affecting the adsorption process including initial Cu(II) concentration, pH, contact time, and temperature were investigated. The adsorption kinetics could be better described by the pseudo second-order model, and the adsorption matches with the Langmuir isotherm. The results indicated that MWCNT-TA possessed higher adsorption capability for Cu(II) than pristine MWCNTs and TA. Additionally, MWCNT-TA can be facilely separated from aqueous solution by centrifugation and filtration after adsorption of Cu(II). Therefore, MWCNT-TA would find its potential application in wastewater treatment in the future. (C) 2015 Elsevier B.V. All rights reserved.