Remediation of waste water by Co-Fe layered double hydroxide and its catalytic activity

Layered double hydroxide (LDH) nanoparticles have tremendous anion-intercalating property. Co-Fe LDH has been synthesized using the ball milling method. Characterization of Co-Fe LDH was done by XRD, SEM, TEM and FT-IR. The prepared LDH was used, for the first time, as a catalyst for multi-walled carbon nanotubes (MWCNTs) via chemical vapor deposition (CVD) of acetylene at different temperatures (400-700 degrees C). Also, the ability of Co-Fe LDH as an adsorbent was investigated for the removal of Cd2+ ions from aqueous solutions. Various physicoechemical parameters such as pH, initial metal ion concentration, and time were studied. To get the adsorption isotherms, the concentrations of the metal ions ranging from 6 to 18 mg/I were used. The adsorption process follows pseudo-second-order reaction kinetics, as well as Langmuir adsorption isotherms. Interestingly, Co-Fe LDH demonstrated 95% Cd2+ removal at pH 9 and 6 h which could be applied in wastewater treatment characterized by a high efficiency and low cost. (C) 2016 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.