@article{UnuabonahElKhaiaryOluOwolabietal.2012,
  author    = {Unuabonah, Emmanuel I. and El-Khaiary, Mohammad I. and Olu-Owolabi, Bamidele I. and Adebowale, Kayode O.},
  title     = {Predicting the dynamics and performance of a polymer-clay based composite in a fixed bed system for the removal of lead (II) ion},
  series = {Chemical engineering research and design},
  volume    = {90},
  journal   = {Chemical engineering research and design},
  number    = {8},
  publisher = {Inst. of Electr. and Electronics Engineers},
  address   = {Rugby},
  issn      = {0263-8762},
  doi       = {10.1016/j.cherd.2011.11.009},
  pages     = {1105 -- 1115},
  year      = {2012},
  abstract  = {A polymer-clay based composite adsorbent was prepared from locally obtained kaolinite clay and polyvinyl alcohol. The composite adsorbent was used to remove lead (II) ions from aqueous solution in a fixed bed mode. The increase in bed height and initial metal ion concentration increased the adsorption capacity of lead (II) and the volume of aqueous solution treated at 50\% breakthrough. However, the adsorption capacity was reduced by almost 16.5\% with the simultaneous presence of Ca2+/Pb2+ and Na+/Pb2+ in the aqueous solution. Regeneration of the adsorbent with 0.1 M of HCl also reduced its adsorption capacity to 75.1\%. Adsorption of lead (II) ions onto the polymer-clay composite adsorbent in the presence of Na+ and Ca2+ electrolyte increased the rate of mass transfer, probably due to competition between cationic species in solution for adsorption sites. Regeneration further increased the rate of mass transfer as a result of reduced adsorption sites after the regeneration process. The length of the mass transfer zone was found to increase with increasing bed height but did not change with increasing the initial metal ion concentration. The models of Yoon-Nelson, Thomas, and Clark were found to give good fit to adsorption data. On the other hand, Bohart-Adams model was found to be a poor predictor for the column operation. The polymer-clay composite adsorbent has a good potential for the removal of lead (II) ions from highly polluted aqueous solutions.},
  language  = {en}
}
@article{OmorogieBabalolaUnuabonahetal.2012,
  author    = {Omorogie, Martins O. and Babalola, Jonathan Oyebamiji and Unuabonah, Emmanuel I. and Gong, Jian Ru},
  title     = {Kinetics and thermodynamics of heavy metal ions sequestration onto novel Nauclea diderrichii seed biomass},
  series = {BIORESOURCE TECHNOLOGY},
  volume    = {118},
  journal   = {BIORESOURCE TECHNOLOGY},
  number    = {8},
  publisher = {ELSEVIER SCI LTD},
  address   = {OXFORD},
  issn      = {0960-8524},
  doi       = {10.1016/j.biortech.2012.04.053},
  pages     = {576 -- 579},
  year      = {2012},
  abstract  = {This study reports the sequestration of Cd(II) and Hg(II) using a new biosorbent. Nauclea diderrichii seed biomass. Experimental data obtained were fitted into kinetic and thermodynamic models. Experimental data fitted best into pseudo-second order kinetic model among others. Results obtained kinetically revealed that the biosorption of Cd(II) and Hg(II) using N. diderrichii seed biosorbent increased with increase in temperature. At the highest temperature, which was 333 K. the highest amount of metal biosorbed, q(e), for Cd(II) and Hg(II) obtained were 6.30 and 6.15 mg/g respectively. The biosorption of Cd(II) was kinetically faster than that of Hg(II), the highest initial biosorption rates for Cd(II) and Hg(II) were 56.19 and 4.39 mg/g min respectively. Thermodynamic parameters obtained by Erying equation from this study revealed that the biosorption process was spontaneous, feasible, endothermic with a decrease in the degree of chaos in the biosorption system. (C) 2012 Elsevier Ltd. All rights reserved.},
  language  = {en}
}