Comparison between activated carbon and multiwall carbon nanotubes in the removal of cadmium(II) and chromium(VI) from water solutions

Research Article| July 12 2014 Comparison between activated carbon and multiwall carbon nanotubes in the removal of cadmium(II) and chromium(VI) from water solutions Ali Naghizadeh Ali Naghizadeh 1Department of Environmental Health Engineering, School of Public Health, Birjand University of Medical Sciences (BUMS), Birjand, Iran E-mail: al.naghizadeh@yahoo.com Search for other works by this author on: This Site PubMed Google Scholar Journal of Water Supply: Research and Technology-Aqua (2015) 64 (1): 64–73. https://doi.org/10.2166/aqua.2014.022 Article history Received: March 06 2014 Accepted: June 19 2014 Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Cite Icon Cite Permissions Search Site Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAll JournalsThis Journal Search Advanced Search Citation Ali Naghizadeh; Comparison between activated carbon and multiwall carbon nanotubes in the removal of cadmium(II) and chromium(VI) from water solutions. Journal of Water Supply: Research and Technology-Aqua 1 February 2015; 64 (1): 64–73. doi: https://doi.org/10.2166/aqua.2014.022 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex This paper evaluates the aqueous cadmium(II) and chromium(VI) adsorption efficiency on multiwall carbon nanotubes and activated carbon (AC). The effects of pH, initial metal ion concentrations, and adsorbent dosage on the adsorption of heavy metal by carbon adsorbents were also evaluated. In addition, this study used the Langmuir and Freundlich isotherms to describe behavior of equilibrium adsorption. It has been shown that the carbon nanotubes (CNTs) sampled exhibited a pH of point of zero charge (pHpzc) of around 6.1 while the AC sample had a pHpzc of about 6.8. Maximum adsorption efficiencies were found at pH 3 for both CNTs and AC. Also, carbon nanotubes have higher adsorption efficiency towards both studied metal ions in comparison with ACs. The capacity of CNTs to adsorb Cd(II) and Cr(VI) was 4.5 and 3.1 mg/g, respectively. Additionally, the capacity of AC to adsorb Cd(II) and Cr(VI) was 2.8 and 2.4 mg/g, respectively. The adsorption percentage of metal ions onto both carbon adsorbents increased as adsorbents dosage and initial metal ion concentrations increased. The equilibrium adsorption of the studied metal ions is best fitted using the Freundlich isotherm. activated carbon, adsorption capacity, carbon nanotubes, metal ions © IWA Publishing 2015 You do not currently have access to this content.