Application of a novel magnetic carbon nanotube adsorbent for removal of mercury from aqueous solutions.
In this research, multiwall carbon nanotube was magnetized and subsequently functionalized by thiosemicarbazide. After characterization by FTIR, BET, SEM, EDAX, and VSM techniques, the magnetized adsorbent (multi-walled carbon nanotubes (MWCNTs)/Fe3O4) was used for removal of Hg2+from aqueous solutions and the experimental conditions were optimized. The adsorption capacity of 172.83 mg g-1was obtained at 25 °C and pH = 3 which was superior to the value obtained for initial multiwall carbon nanotube, magnetized sample, and many previously reported values. In the presence of Pb+2and Cd+2, the adsorbent was selective towards mercury when their concentration was respectively below 50 and 100 mg L-1. The adsorption process was kinetically fast and the equilibration was attained within 60 min with 69.5% of the capacity obtained within 10 min. The used adsorbent was regenerated by HNO3solution, and the regenerated adsorbent retained 92% of its initial capacity. The magnetic sensitivity of the adsorbent allowed the simple separation of the used adsorbent from the solution by implying an appropriate external magnetic field. The adsorption data was well fitted to the Langmuir isotherm model, indicating homogeneous and monolayer adsorption of mercury by the adsorbent.
Department of Chemistry, Islamic Azad University, Shahreza Branch, P.O. Box 311-86145, Shahreza, Iran.
Farshid
F
Homayoon
Department of Chemistry, Islamic Azad University, Shahreza Branch, P.O. Box 311-86145, Shahreza, Iran. faghihian@iaush.ac.ir.
Hossein
H
Faghihian
Department of Chemistry, Islamic Azad University, Shahreza Branch, P.O. Box 311-86145, Shahreza, Iran.
Firoozeh
F
Torki
D000327:Adsorption; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008628:Mercury / Q000737:chemistry*; D037742:Nanotubes, Carbon / Q000737:chemistry*; D012996:Solutions; D014874:Water Pollutants, Chemical / Q000737:chemistry*
D037742:Nanotubes, Carbon; D012996:Solutions; D014874:Water Pollutants, Chemical; D008628:Mercury
Adsorption; Functionalization; Magnetized carbon nanotubes; Mercury; Thiosemicarbazide