Disinfection of water with new chitosan-modified hybrid clay composite adsorbent.
Heliyon 2017;
3:e00379. [PMID:
29296686 PMCID:
PMC5741170 DOI:
10.1016/j.heliyon.2017.e00379]
[Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2017] [Revised: 07/17/2017] [Accepted: 08/02/2017] [Indexed: 11/23/2022] Open
Abstract
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.
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