Agrogenic Modified Clay For The Removal Of Gram-Negative Bacteria From Water
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Date
2016-08
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Publisher
run.edu.ng
Abstract
The presence of pathogens in the few available water resources which have been reported to
cause diseases and subsequent deaths especially in children of ages less than five years have
given rise to the development of cost-effective, environmentally friendly, efficient and
convenience means of water treatment. This project reports on the preparation of Zn-modified kaolinite clay biomass Carica papaya seeds and Musa paradisiaca peels) composite adsorbents for the removal of some enteric bacteria (E. coli, S. typhi and V. cholerae ) from the water. Three composite adsorbents were prepared: Zn-modified kaolinite clay adsorbent and Carica papaya seeds (ZKPS); Zn-modified kaolinite clay and plantain peels (ZKPP) and Zn-modified kaolinite clay-papaya seeds and plantain peels (ZKPPPS). The mixtures were treated to microwave at 500 W for 10 min and washed to neutral pH. The characterization with SEM shows they are homogeneous composites, while electron mapping results showed the presence of elements obtainable from the composites. The EDX analysis confirmed the presence of the all the elements contained in the composites
and their varying concentration in which Zn was observed to be highest in all the composite
adsorbents. Fourier Transformed Infrared spectroscopy and X-ray Diffraction (XRD) indicates
chemical functionalities involved in the interaction between Carica papaya seeds and/or plantain peels with kaolinite in the presence of an activating agent. The FTIR spectra did confirm the presence of Zn in the composite adsorbents at ca. 462 cm-1. Surface area analysis via N2 sorption shows that ZKPP composite adsorbent has the highest surface area (342 m2
/g), followed by ZKPPPS composite adsorbent with 150 m2/g while ZKPS composite adsorbent had 117 m2/g. Surface area results suggest that the particles sizes of the composite adsorbents were in the nanoscale. The pH point of zero charges (pHpzc) of the composites adsorbents were obtained to be 7.0 for ZKPP and ZKPS composites adsorbents, while that of ZKPPPS composite adsorbent was obtained to 6.47 in contrast to that of kaolinite clay obtained to 4.98. This implies that at a temperature below pHpzc the adsorption of negatively charged particles are favored. Bacterial removal activities of the three composite adsorbent showed that ZKPS composite adsorbent had better activity on S. typhi and V. cholerae because the breakthrough time was observed at 700 min (5.6 L) and 400 min (3.2 L) respectively followed by ZKPP composite adsorbent with 400 min (3.2 L) respectively for S. typhi and V. cholerae, while ZKPPPS composite adsorbent was less efficient on the two bacteria with 275 min and 200 min for S. typhi and V. cholerae respectively. The three composite adsorbents showed no good efficiency for the removal of Escherichia coli from water.
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Keywords
Composite adsorbents, Biomasse, Enteric bacteria, Pathogens, Carica papaya seeds, Musa paradisiaca peels
Citation
Daniel T. Koko (2016) Agrogenic Modified Clay For The Removal Of Gram-Negative Bacteria From Water. Thesis