Ho, Choon Sin (2021) Characterisation of deformation behaviour and damage progression of recycled aluminium alloy AA6061. Doctoral thesis, Universiti Tun Hussein Malaysia.
|
Text
24p HO CHOON SIN.pdf Download (798kB) | Preview |
|
![[img]](http://eprints.uthm.edu.my/style/images/fileicons/text.png) |
Text (Copyright Declaration)
HO CHOON SIN COPYRIGHT DECLARATION.pdf Restricted to Repository staff only Download (498kB) | Request a copy |
|
|
Text (Full Text)
HO CHOON SIN WATERMARK.pdf Restricted to Registered users only Download (35MB) | Request a copy |
Abstract
Fungi have unique characteristics since they have several applications in the environment and industry due to its ability to produce the different enzyme. This study aims to isolate a new fungal strain from Pontian peatland, Johor, Malaysia to be used for dye decolourizing in the synthetic greywater as a function of laccase (LAC), manganese peroxidase (MnP) and lignin peroxidase (LiP). The bio-synthesized nanoparticles (bimetallic Zn/Cu NPs) in the secondary metabolic products generated during the enzyme production in pumpkin peels medium was evaluated for inactivating Escherichia coli and Staphylococcus aureus seeded in greywater. The fungal isolates were identified according to phenotypic characteristics and by molecular characteristic at D1/D2 region and ITS (ITS1- ITS4) sequences. The decolourization, enzyme production and inactivation process were optimised using response surface methodology (RSM). The mechanism of decolourization and inactivation process was investigated based on Field Emission Scanning Electron Microscopy with Energy Dispersive X-Ray Spectroscopy (FESEMEDX), Fourier transforms infrared spectroscopy (FTIR), atomic force microscopy (AFM) and Raman Spectroscopy analysis. The results revealed that Aspergillus iizukae EAN605, Aspergillus arenarioides EAN603, Penicillium pedernalense EAN604, Purpureocillium lilacinum EAN601, Paraconiothyrium brasiliense EAN202 and Parengyodontium album EAN602 were new strains and first time recorded in Malaysia. The best dye decolourization (78.34%) was 57.15 mg 100 mL of dye, pH 6 and after 8.5 days (R -1 2 of pumpkin peels, =77.9%). The oxidative enzyme production was recorded with 20 g 100 mL -1 of inoculum size, at pH 5.5 and after 10 days, where 6.15, 2.58 and 127.99 U mg 1 , 4.6 mL/100 mL -1 of LAC, MnP and LiP was produced, respectively. The inactivation of E. coli and S. aureus by Zn/Cu NPs was effective with 0.028 mg mL -1 of Zn/Cu NPs, at pH 6 and after 60 mins with 5.6 and 5.2 log reduction respectively. The decolourization mechanism took place due to the action of oxidative enzymes on the inner membrane of fungal mycelium and in the surrounded medium. The inactivation process acts by the destruction of the chemical composition of the bacterial cell wall and membrane. In conclusion, this study demonstrates that peatland has high fungal diversity to be used in the dye decolourization and synthesis of NPs for inactivating pathogenic bacteria in the greywater. -1
| Item Type: | Thesis (Doctoral) |
|---|---|
| Subjects: | T Technology > T Technology (General) T Technology > TA Engineering (General). Civil engineering (General) > TA401-492 Materials of engineering and construction. Mechanics of materials |
| Divisions: | Faculty of Mechanical and Manufacturing Engineering > Department of Mechanical Engineering |
| Depositing User: | Mrs. Sabarina Che Mat |
| Date Deposited: | 05 Feb 2022 07:13 |
| Last Modified: | 05 Feb 2022 07:13 |
| URI: | http://eprints.uthm.edu.my/id/eprint/4943 |
Actions (login required)
 |
View Item |