| dc.description.abstract | This thesis aims to utilize cuttlefish bone (CFB), a biowaste, into sustainable materials for water remediation. CFB is a biological waste mainly composed of aragonite (85%), a calcium carbonate (CaCO3) mineral. Appropriate physical/thermal/chemical processing of CaCO3 from CFB into stable powders and self-standing membranes has proved a valid route for water remediation applications. For the removal of methylene blue (MB) a model compound for dye colours and Escherichia coli (E-coli) bacteria from contaminated waters in the laboratory environment. First, highly ordered and stable calcium oxide (CaO) in a multiple cubes structure was synthesized from CFB via calcination. CFB was calcined at two high temperatures, 900 ℃ and 1000 ℃ for 0.5 h and 1.0 h dwell times to analyse the effect of high temperature concerning dwell time on the CaO morphological and chemical characteristics and their performance in the adsorption of MB. Langmuir adsorption isotherm (R2 = 0.94) showed a monolayer adsorption mechanism consistent with a pseudo-second-order model (R2 = 0.98). Second, antibacterial biopolymer chitosan was obtained from CFB via a chemical extraction route. The eight different extraction protocols were performed to see the effect of different parameters such as acid molarity, extraction temperature and processing time, to see acid vs alkaline effects on the yield of chitin, its morphology, and the crystalline structure. The extracted chitin was further deacetylated using 1M Sodium hydroxide (NaOH) to convert it into a polysaccharide antibacterial biopolymer called chitosan. The extracted chitosan was tested for its antibacterial properties using a gram-negative bacterial strain, E-coli. Finally, a polymeric antibacterial membrane was prepared by mixing different chitosan concentrations with 10% (w/w) Polyvinyl Alcohol (PVA). Self-standing antibacterial 6 membranes in the laboratory environment were prepared through a very simple technique called casting. The antibacterial properties were tested with the same gram-negative bacterial strain E-coli. Different concentrations of chitosan, using different chitosan-PVA ratios were used to assess the membrane stability and antibacterial properties. The most suitable working ratio for the antibacterial assay was 20% (w/v)) concentrated chitosan with 10% (w/w) PVA with a ratio of 1:1 (v:v). These membranes showed 98% bacterial removal efficiency as compared to other chitosan-based membranes. The 500 ul of 20% (w/v) concentrated chitosan showed similar antibacterial properties to 6% (v/v) Carbenicillin, a subgroup of the standard penicillin antibiotics. | en_US |
