Vigneswar a/l Krishnan (2018) Ultrasonic assisted photodegradation of reactive black 5 by zinc oxide impregnated activated red mud catalyst. Masters thesis, Universiti Malaysia Sabah.
![[img]](https://eprints.ums.edu.my/style/images/fileicons/text.png) |
Text
24 PAGES.pdf Download (953kB) |
|
Text
FULLTEXT.pdf Restricted to Registered users only Download (9MB) |
Abstract
This study focuses on the remediation of the anionic dye contaminated wastewater using the prepared ZnO/ ARM sonophotocatalyst. In this AOP process, an anionic dye, Reactive black 5, is subjected to the sonophotocatalytic treatment process with the aim of establishing the effectiveness of the prepared ZnO doped activated red mud (ZnO/ ARM) as sonophotocatalyst. ZnO/ ARM was prepared by impregnation method at different weight ratios (0.25:1, 0.5:1, 0.75:1 and 1:1) and the ZnO/ARM at weight ratio of 0.75: 1 was chosen as effective photocatalyst. The prepared sonophotocatalyst were characterized by XRD, BET, FTIR, SEM-EDX, DRS and PL. Parametric and kinetics studies for the removal of RBS from the simulated wastewater were conducted to confirm the effectiveness of this sonophotocatalyst. A transducer sonicator (35 kHz) and a UV-C (254 nm) lamp were applied simultaneously to effectively degrade the selected recalcitrant dye-based pollutant. The influence of the solution pH, concentration and catalyst dosage were manipulated throughout this study to investigate the sonophotodegradation kinetics and synergistic effects on the RBS degradation. Experimental results confirmed that the sonophotocatalysis rate of 20 ppm of RBS was better under acidic medium (66.7%) in comparison to alkaline medium (46.1%) due to the surface charge of the catalyst. At acidic condition, a positive charge excess in the ZnO/ARM surface favours a strong electrostatic interaction with 503- groups of the dye which is then consequently resulted in the higher degradation rate (0.0156 min-1). Meanwhile at alkaline condition, catalytic activity of ZnO/ ARM was diminished by the excess negative charge which promotes the repulsion of dye in ZnO/ ARM surfaces which recorded degradation rate of 0.01 min-1. The band gap energy E9 of the ARM was found to be 1.98 eV and the prepared ZnO/ARM (0.75:1)=2.04 eV. The introduction of ZnO does not strongly affect the optical absorption property of ARM. The accelerated photo induced electron-hole transfer and separation, decreased recombination rate and band energy matching lead to the enhancement of photocatalytic performance for Zn0/ ARM composite. Synergistic effects were analyzed based on the first order kinetic rate model, and it was found that the synergistic effect was observed for all the experiments conducted.
| Item Type: | Thesis (Masters) |
|---|---|
| Keyword: | Zno, Arm composite, Activated red mud, Reactive black 5, Anionic dye degradation, Sonophotocatalysis |
| Subjects: | Q Science > QD Chemistry > QD1-999 Chemistry > QD450-801 Physical and theoretical chemistry > QD701-731 Photochemistry |
| Department: | FACULTY > Faculty of Science and Natural Resources |
| Depositing User: | DG MASNIAH AHMAD - |
| Date Deposited: | 11 Jun 2025 15:29 |
| Last Modified: | 11 Jun 2025 15:29 |
| URI: | https://eprints.ums.edu.my/id/eprint/44076 |
Actions (login required)
 |
View Item |