@article{UnuabonahKolawoleAgunbiadeetal.2017,
  author    = {Unuabonah, Emmanuel I. and Kolawole, Matthew O. and Agunbiade, Foluso O. and Omorogie, Martins O. and Koko, Daniel T. and Ugwuja, Chidinma G. and Ugege, Leonard E. and Oyejide, Nicholas E. and G{\"u}nter, Christina and Taubert, Andreas},
  title     = {Novel metal-doped bacteriostatic hybrid clay composites for point-of-use disinfection of water},
  series = {Journal of Environmental Chemical Engineering},
  volume    = {5},
  journal   = {Journal of Environmental Chemical Engineering},
  publisher = {Elsevier},
  address   = {Oxford},
  issn      = {2213-3437},
  doi       = {10.1016/j.jece.2017.04.017},
  pages     = {2128 -- 2141},
  year      = {2017},
  abstract  = {This study reports the facile microwave-assisted thermal preparation of novel metal-doped hybrid clay composite adsorbents consisting of Kaolinite clay, Carica papaya seeds and/or plantain peels (Musa paradisiaca) and ZnCl2. Fourier Transformed IR spectroscopy, X-ray diffraction, Scanning Electron Microscopy and Brunauer-Emmett-Teller (BET) analysis are employed to characterize these composite adsorbents. The physicochemical analysis of these composites suggests that they act as bacteriostatic rather than bacteriacidal agents. This bacterostactic action is induced by the ZnO phase in the composites whose amount correlates with the efficacy of the composite. The composite prepared with papaya seeds (PS-HYCA) provides the best disinfection efficacy (when compared with composite prepared with Musa paradisiaca peels-PP-HYCA) against gram-negative enteric bacteria with a breakthrough time of 400 and 700 min for the removal of 1.5 x10(6) cfu/mL S. typhi and V. cholerae from water respectively. At 10(3) cfu/mL of each bacterium in solution, 2 g of both composite adsorbents kept the levels the bacteria in effluent solutions at zero for up to 24 h. Steam regeneration of 2 g of bacteria-loaded Carica papaya prepared composite adsorbent shows a loss of ca. 31\% of its capacity even after the 3rd regeneration cycle of 25 h of service time. The composite adsorbent prepared with Carica papaya seeds will be useful for developing simple point-of-use water treatment systems for water disinfection application. This composite adsorbent is comparatively of good performance and shows relatively long hydraulic contact times and is expected to minimize energy intensive traditional treatment processes.},
  language  = {en}
}
@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}
}