Preparation, characterisation and application of iron oxide-chitosan nanocomposites as flocculants for palm oil mill effluent
<p>This research aimed to prepare, characterise and apply four iron oxide-chitosan</p><p>nanocomposites, namely ferrihydrite-chitosan (FC), goethite-chitosan (GC), hematitechitosan</p><p>(HM) and magnetite-chitosan (MC) as floccul...
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| Format: | thesis |
| Language: | eng |
| Published: |
2022
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| Subjects: | |
| Online Access: | https://ir.upsi.edu.my/detailsg.php?det=9499 |
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| Summary: | <p>This research aimed to prepare, characterise and apply four iron oxide-chitosan</p><p>nanocomposites, namely ferrihydrite-chitosan (FC), goethite-chitosan (GC), hematitechitosan</p><p>(HM) and magnetite-chitosan (MC) as flocculants for the pre-treatment of palm</p><p>oil mill effluent (POME). The nanocomposites were prepared through a co-precipitation</p><p>method at three (w/w) ratios of iron oxide to chitosan. The physicochemical properties of</p><p>nanocomposites were characterised by using a scanning electron microscope (SEM),</p><p>X-ray diffraction (XRD) spectrometer, Fourier transform infrared (FTIR) spectrometer,</p><p>vibrating sample magnetometer (VSM) and thermogravimetric analyser (TGA) before</p><p>and after flocculation experiments to prove the effectiveness of the nanocomposites. The</p><p>effects of flocculant dosage, solution pH and settling time on flocculation for the removal</p><p>of total suspended solids (TSS), turbidity, chemical oxygen demand (COD), oil and</p><p>grease (O&G) and nutrients (K, Fe, Mn and Cu) were investigated by jar test method.</p><p>Research findings found that the MC nanocomposite with a ratio of 1:1 (w/w) showed the</p><p>highest percentage of contaminant reduction. The optimal conditions for the reduction of</p><p>all contaminants were achieved at a flocculant dosage of 1.5 g/L, pH of 5.0 and a settling</p><p>time of 60 minutes. Under this condition, the reduction of TSS, turbidity, COD and O&G</p><p>was 86.79%, 82.61%, 74.28% and 62.64%, respectively. After three cycles of</p><p>flocculation/deflocculation process, MC nanocomposite retained flocculation efficiency</p><p>and flocculants recovery in the range of 66.7-85.7% and 83-91%, respectively.</p><p>Combination of charge neutralisation and polymer bridging was the main mechanism of</p><p>interaction between nanocomposite and POME contaminants. In conclusion, the iron</p><p>oxide incorporated chitosan has increased the properties and flocculation performance of</p><p>the nanocomposite as compared to conventional flocculants. In implication, iron oxidechitosan</p><p>nanocomposites potentially act as alternative flocculants for pre-treatment of</p><p>POME due to having simplicity, recyclability and environmental friendly properties.</p> |
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