title: Rapid adsorption of toxic Pb(II) ions from aqueous solution using multiwall carbon nanotubes synthesized by microwave chemical vapor deposition technique.
abstract: Multiwall carbon nanotubes (MWCNTs) were synthesized using a tubular microwave chemical vapor deposition technique, using acetylene and hydrogen as the precursor gases and ferrocene as catalyst. The novel MWCNT samples were tested for their performance in terms of Pb(II) binding. The synthesized MWCNT samples were characterized using Fourier Transform Infrared (FT-IR), Brunauer, Emmett and Teller (BET), Field Emission Scanning Electron Microscopy (FESEM) analysis, and the adsorption of Pb(II) was studied as a function of pH, initial Pb(II) concentration, MWCNT dosage, agitation speed, and adsorption time, and process parameters were optimized. The adsorption data followed both Freundlich and Langmuir isotherms. On the basis of the Langmuir model, Qmax was calculated to be 104.2mg/g for the microwave-synthesized MWCNTs. In order to investigate the dynamic behavior of MWCNTs as an adsorbent, the kinetic data were modeled using pseudo first-order and pseudo second-order equations. Different thermodynamic parameters, viz., ∆H(0), ∆S(0) and ∆G(0) were evaluated and it was found that the adsorption was feasible, spontaneous and endothermic in nature. The statistical analysis revealed that the optimum conditions for the highest removal (99.9%) of Pb(II) are at pH5, MWCNT dosage 0.1g, agitation speed 160r/min and time of 22.5min with the initial concentration of 10mg/L. Our results proved that microwave-synthesized MWCNTs can be used as an effective Pb(II) adsorbent due to their high adsorption capacity as well as the short adsorption time needed to achieve equilibrium.
authors.affiliation: Department of Chemical Engineering, Faculty of Engineering and Science, Curtin University Sarawak, 98009, Malaysia; Department of Chemical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia. Electronic address: mubarak.yaseen@gmail.com.
authors.forename: Nabisab Mujawar
authors.initials: NM
authors.lastname: Mubarak
authors.affiliation: Petroleum and Chemical Engineering Programme Area, Faculty of Engineering, Institut Teknologi Brunei, Tungku Gadong, Brunei Darussalam. Electronic address: jay_sahu@yahoo.co.in.
authors.forename: Jaya Narayan
authors.initials: JN
authors.lastname: Sahu
authors.affiliation: Malaysia-Japan International Institute of Technology, Universiti Teknologi Malaysia, Jalan Semarak, 54100 Kuala Lumpur, Malaysia.
authors.forename: Ezzat Chan
authors.initials: EC
authors.lastname: Abdullah
authors.affiliation: Department of Chemical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia.
authors.forename: Natesan Subramanian
authors.initials: NS
authors.lastname: Jayakumar
mesh_terms: D000327:Adsorption; D007700:Kinetics; D007854:Lead / Q000737:chemistry*; D008872:Microwaves; D008956:Models, Chemical; D037742:Nanotubes, Carbon / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013816:Thermodynamics; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D037742:Nanotubes, Carbon; D014874:Water Pollutants, Chemical; D007854:Lead
keywords: Adsorption; Heavy metal; Lead; MWCNTs; Microwave; Wastewater treatment