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

• Published in: Journal of the Taiwan Institute of Chemical Engineers 2017-02, Vol.71, p.441-453
• Main Authors: Moaty, S.A. Abdel, Farghali, A.A., Moussa, M., Khaled, Rehab
• Format: Article
• Language: English
• Subjects: Adsorption; Cadmium ions; Cobalt–iron; LDH; MWCNTs; Wastewater
• ISSN: 1876-1070; 1876-1089
• DOI: 10.1016/j.jtice.2016.12.001

•Preparation and characterization of Co–Fe LDH.•Catalytic activity of Co–Fe LDH for CNTs production.•Removal of heavy metals, as Cd+2 using Co–Fe LDH.•Kinetic analysis for adsorption process. 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°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 18mg/l 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 6h which could be applied in wastewater treatment characterized by a high efficiency and low cost. [Display omitted]