Photocatalytic degradation of diclofenac in aquatic water using natural photosensitizer | |
| Author | Tripathy, Diwesh |
| Call Number | AIT Thesis no.FB-21-02 |
| Subject(s) | Photocatalysis Photochemical oxidants--Environmental aspects Photosensitization, Biological |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Food Engineering and Bioprocess Technology, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no.FB-21-02 |
| Abstract | In recent times, Diclofenac is considered as a persistent pharmaceutical contaminant, and their efficacious elimination from water matrices especially in aquatic environment has been a major rising concern. This research assesses the applicability of natural photosensitizer Magnesium Chlorophyllin (Mg-Chl) in presence of blue light irradiation for the photosensitized treatment of contaminant Diclofenac. This study calculated the inter-relationship between concentration of photosensitizer, real intensity, and irradiation time as a function of real number of absorbed photons (Nph) by the photocatalytic system. The relationship was applied to develop three treatment conditions (TC-I, II & III) for photocatalysis of DCF which resulted in same rate of degradation when same absorbed photons (Nph) were applied, eventually which validated our main hypothesis of this study. It was observed that, in presence of 200 ppm Mg-Chl, 75% degradation of DCF was achieved at light dose of 1.031021 photons/cm3 . The degradation kinetics of DCF were fitted with first-order-reaction model (R2 > 0.98). The reaction rate constant and half-life time of DCF in aqueous solution was found to be 0.0106 ± 0.0002 min-1 and 65.07 min, respectively. Moreover, the results were demonstrated through contour plots of degradation rate of DCF as a function of concentration of photosensitizer and radiant fluence of the treatment parameters. The contour plots showed the accurate efficacy of the photocatalytic removal of DCF regardless of treatment conditions. In addition, quantum yield of singlet oxygen (1O2) of Mg-Chl under blue light was 0.38 which indicated that degradation of DCF is dominated by Type-II photosensitization reaction through generation of ROS 1O2. The application of this study was applied for the treatment of DCF spiked aquatic samples which showed total removal of DCF in different pH level (6.5, 7 & 8.5) at a light dose of 1.035 1021 photons/cm3 . Moreover, the quantum yield of DCF aquatic samples in pH 8.5 was found to be 7.810-5 which showed the photochemical efficiency. In conclusion, natural photosensitizer Mg-Chl was effectively applicable to treat the contaminants DCF in real samples as well. |
| Year | 2021 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no.FB-21-02 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Food, Agriculture and Natural Resources (Former title: Department of Food Agriculture, and BioResources (DFAB)) |
| Academic Program/FoS | Food Engineering and Bioprocess Technology (FB) |
| Chairperson(s) | Loc Thai Nguyen; |
| Examination Committee(s) | Anal, Anil Kumar;Datta, Avishek; |
| Scholarship Donor(s) | Her Majesty the Queen's Scholarships (Thailand); |
| Degree | Thesis (M. Sc.) - Asian Institute of Technology, 2021 |