Disinfection of water with new chitosan-modified hybrid clay composite adsorbent
Emmanuel I. Unuabonah,
Adewale Adewuyi,
Matthew O. Kolawole,
Martins O. Omorogie,
Olalekan C. Olatunde,
Scott O. Fayemi,
Christina Günter,
Chukwunonso P. Okoli,
Foluso O. Agunbiade,
Andreas Taubert
Affiliations
Emmanuel I. Unuabonah
Environmental & Chemical Processes Research Laboratory, Department of Chemical Sciences, Redeemer’s University, P.M.B 230, Ede, Osun State, Nigeria
Adewale Adewuyi
Environmental & Chemical Processes Research Laboratory, Department of Chemical Sciences, Redeemer’s University, P.M.B 230, Ede, Osun State, Nigeria
Matthew O. Kolawole
Department of Microbiology, University of Ilorin, Ilorin, Kwara State, Nigeria
Martins O. Omorogie
Environmental & Chemical Processes Research Laboratory, Department of Chemical Sciences, Redeemer’s University, P.M.B 230, Ede, Osun State, Nigeria
Olalekan C. Olatunde
Environmental & Chemical Processes Research Laboratory, Department of Chemical Sciences, Redeemer’s University, P.M.B 230, Ede, Osun State, Nigeria
Scott O. Fayemi
Department of Biological Sciences, Redeemer's University, P.M.B 230, Ede, Osun State, Nigeria
Christina Günter
Department of Earth and Environmental Science, University of Potsdam, D-14476 Potsdam, Germany
Chukwunonso P. Okoli
Adsorption & Catalysis Research Laboratory, Department of Chemistry, Vaal University of Technology, Private Bag X021, Andries Potgieter Boulevard, Vanderbijlpark, 1900, South Africa
Foluso O. Agunbiade
Environmental & Chemical Processes Research Laboratory, Department of Chemical Sciences, Redeemer’s University, P.M.B 230, Ede, Osun State, Nigeria
Andreas Taubert
Institute of Chemistry, University of Potsdam, D-14476 Potsdam, Germany
Hybrid clay composites were prepared from Kaolinite clay and Carica papaya seeds via modification with chitosan, Alum, NaOH, and ZnCl2 in different ratios, using solvothermal and surface modification techniques. Several composite adsorbents were prepared, and the most efficient of them for the removal of gram negative enteric bacteria was the hybrid clay composite that was surface-modified with chitosan, Ch-nHYCA1:5 (Chitosan: nHYCA = 1:5). This composite adsorbent had a maximum adsorption removal value of 4.07 × 106 cfu/mL for V. cholerae after 120 min, 1.95 × 106 cfu/mL for E. coli after ∼180 min and 3.25 × 106 cfu/mL for S. typhi after 270 min. The Brouers-Sotolongo model was found to better predict the maximum adsorption capacity (qmax) of Ch-nHYCA1:5 composite adsorbent for the removal of E. coli with a qmax of 103.07 mg/g (7.93 × 107 cfu/mL) and V. cholerae with a qmax of 154.18 mg/g (1.19 × 108 cfu/mL) while the Sips model best described S. typhi adsorption by Ch-nHYCA1:5 composite with an estimated qmax of 83.65 mg/g (6.43 × 107 cfu/mL). These efficiencies do far exceed the alert/action levels of ca. 500 cfu/mL in drinking water for these bacteria. The simplicity of the composite preparation process and the availability of raw materials used for its preparation underscore the potential of this low-cost chitosan-modified composite adsorbent (Ch-nHYCA1:5) for water treatment.
