Abstract
The occurrence of emerging pharmaceutical contaminants, especially antibiotics in water systems is an alarming issue and is addressed using Advanced Oxidation Processes (AOPs). In this study, the degradation of antibiotic tetracycline hydrochloride (TCT) is evaluated using UV and solar light as the source of energy in the presence of semiconductor oxide catalyst ZnO. The results of the removal efficiency of TCT using UV is slightly less than that of solar light. Solar energy as a source of irradiation is economically feasible, follow-up studies is carried out under solar light. Further, the effective solar photocatalytic degradation of TCT in distilled water and aquaculture wastewater is deeply investigated. TCT showed a 62% degradation efficiency in deionized water at the laboratory scale, while aquaculture effluent exhibited 87% degradation efficiency with the ZnO catalyst after 60 min of solar irradiation. The effect of multiple contaminants such as chloroquine (CLQ) and sulphamethoxazole (SMX) on TCT degradation is also investigated. CLQ inhibited the degradation of TCT, whereas SMX did not. The effective operational parameters, such as pH, irradiation time, photocatalyst dosage, the effect of oxidants, the effect of anions, and TCT concentration, were studied consecutively. The pseudo-first-order kinetic model best fit the experimental results (different tetracycline concentrations). Complete COD removal of TCT concentrations is achieved in deionized (≈90 mg/L) and aquaculture wastewater. The catalyst was characterized using SEM, TEM, and XRD images. LC-QTOF analysis was used to identify the intermediates formed during the degradation using a mechanistic pathway. The results suggest the possibility of using inexpensive natural and non-renewable solar energy to purify TCT-contaminated real wastewater, thereby enabling the reuse of scarce water resources.
Keywords:
photocatalysis; ZnO; tetracycline; chloroquine; sulphamethoxazole; aquaculture; degradation; efficiency Supplementary Materials
The following supporting information can be downloaded at: https://www.mdpi.com/article/10.3390/proceedings2024105002/s1. Conference presentation.
Author Contributions
P.V.G. conceived the idea, researched, and wrote the manuscript. D.N. reviewed the manuscript. S.J. did overall supervision and gave suggestions for improving the manuscript. All authors have read and agreed to the published version of the manuscript.
Funding
This research received funding (by providing necessary facilities, equipment, materials, etc.) from Kerala University of Fisheries and Ocean Studies (KUFOS), Panangad, Ernakulam as a doctoral fellowship for the first author. The sample’s characterization and the lab facility were received from St. Alberts College, Autonomous, Ernakulam.
Institutional Review Board Statement
All ethics were followed during the study and preparation of the manuscript.
Informed Consent Statement
Not applicable.
Data Availability Statement
The datasets generated during the current study are available from the corresponding author upon reasonable request.
Conflicts of Interest
The authors declare no competing interests.
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