@article{OmorogieBabalolaUnuabonahetal.2016,
  author    = {Omorogie, Martins O. and Babalola, Jonathan Oyebamiji and Unuabonah, Emmanuel I. and Song, Weiguo and Gong, Jian Ru},
  title     = {Efficient chromium abstraction from aqueous solution using a low-cost biosorbent: Nauclea diderrichii seed biomass waste},
  series = {Journal of Saudi Chemical Society},
  volume    = {20},
  journal   = {Journal of Saudi Chemical Society},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {1319-6103},
  doi       = {10.1016/j.jscs.2012.09.017},
  pages     = {49 -- 57},
  year      = {2016},
  abstract  = {Toxic Cr(III) which poses environmental hazard to flora and fauna was efficiently abstracted by low-cost Nauclea diderrichii seed biomass (NDS) with good sequestral capacity for this metal was investigated in this study. The NDS surface analyses showed that it has a specific surface area of 5.36 m(2)/g and pHpzc of 4.90. Thermogravimetric analysis of NDS showed three consecutive weight losses from 50-200 degrees C (ca. 5\%), 200-400 C (ca. 35\%), >400 degrees C (ca. 10\%), corresponding to external water molecules, structural water molecules and heat induced condensation reactions respectively. Differential thermogram of NDS presented a large endothermic peak between 20-510 degrees C suggesting bond breakage and dissociation with the ultimate release of small molecules. The experimental data showed kinetically fast biosorption with increased initial Cr(III) concentrations, indicating the role of external mass transfer mechanism as the rate controlling mechanism in this adsorption process. The Langmuir biosorption capacity of NDS was 483.81 mg/g. The use of the corrected Akaike Information Criterion tool for ranking equilibrium models suggested that the Freundlich model best described the experimental data, which is an indication of the heterogeneous nature of the active sites on the surface of NDS. N. diderrichii seed biomass is an easily sourced, cheap and environmental friendly biosorbent which will serve as a good and cost effective alternative to activated carbon for the treatment of polluted water and industrial effluents. (C) 2012 King Saud University. Production and hosting by Elsevier B.V. All rights reserved.},
  language  = {en}
}
@article{OmorogieBabalolaUnuabonahetal.2016,
  author    = {Omorogie, Martins O. and Babalola, Jonathan Oyebamiji and Unuabonah, Emmanuel I. and Gong, Jian R.},
  title     = {Clean technology approach for the competitive binding of toxic metal ions onto MnO2 nano-bioextractant},
  series = {Clean technologies and environmental policy},
  volume    = {18},
  journal   = {Clean technologies and environmental policy},
  publisher = {Springer},
  address   = {New York},
  issn      = {1618-954X},
  doi       = {10.1007/s10098-015-1004-z},
  pages     = {171 -- 184},
  year      = {2016},
  abstract  = {The competitive extraction of Cr(III) onto Nauclea diderrichii seed epicarp doped with MnO2 nanoparticles (MnO2 nano-bioextractant (MNB)) in a single and binary batch system was studied. For validity of experimental data, chi square test, root mean square error, sum of the square errors, hybrid fractional error function, Marquart's percent standard deviation and standard absolute error were used. Among the kinetic models used, pseudo-second-order and Langmuir equations gave the best fits for the experimental data, with qe (mg g) for the uptake of Cr(III) in single metal system onto MNB, then Cr(III) with Cd(II), Pb(II), Hg(II), KCl and CaCl2 in binary metal systems onto MNB were 2.611, then 1.989, 1.016, 2.208, 1.249 and 1.868 from kinetic standpoint, respectively. The initial sorption rates, h (mg/g/min), and half lives, t1/2 (min), for the uptake of Cr(III) in single metal system onto MNB, then Cr(III) with Cd(II), Pb(II), Hg(II), KCl and CaCl2 in binary metal system onto MNB were 3.497, then 2.311, 2.274, 0.242, 2.956, 45.568 and 0.747, then 5.769, 1.766, 12.144, 1.762, and 2.415, respectively. Physicochemical surface analyses such as pH of point of zero charge, Brunauer-Emmett-Teller single point and multi-point techniques for surface area analyses, scanning electron microscopy and transmission electron microscopy were done on MNB and MnO2 nanoparticles in order to understand their surface microstructures. Desorption study showed that MNB can be recycled and used for future study. Hence, MNB showed good potential to remediate Cr(III) from wastewaters and polluted water.},
  language  = {en}
}