Photocatalytic degradation of four emerging antibiotic contaminants and toxicity assessment in wastewater: A comprehensive study

Manisha Sharma; Deepanshi Rajput; Vinod Kumar; Indu Jatain; Tejraj M Aminabhavi; Gunda Mohanakrishna; Ravi Kumar; Kashyap Kumar Dubey

doi:10.1016/j.envres.2023.116132

Photocatalytic degradation of four emerging antibiotic contaminants and toxicity assessment in wastewater: A comprehensive study

Environ Res. 2023 Aug 15;231(Pt 2):116132. doi: 10.1016/j.envres.2023.116132. Epub 2023 May 18.

Authors

Manisha Sharma¹, Deepanshi Rajput², Vinod Kumar³, Indu Jatain¹, Tejraj M Aminabhavi⁴, Gunda Mohanakrishna⁴, Ravi Kumar¹, Kashyap Kumar Dubey⁵

Affiliations

¹ Department of Biotechnology, Central University of Haryana, Mahendergarh, Haryana, 123 031, India.
² Biomanufacturing and Process Development Laboratory, School of Biotechnology, Jawaharlal Nehru University, New Delhi, 110 067, India.
³ Special Centre for Nano Science, Jawaharlal Nehru University, New Delhi, 110 067, India.
⁴ Center for Energy and Environment, School of Advanced Sciences, KLE Technological University, Hubballi, 580 031, Karnataka, India.
⁵ Biomanufacturing and Process Development Laboratory, School of Biotechnology, Jawaharlal Nehru University, New Delhi, 110 067, India. Electronic address: kashyapdubey@jnu.ac.in.

PMID: 37207734
DOI: 10.1016/j.envres.2023.116132

Abstract

Excessive usage and unrestricted discharge of antibiotics in the environment lead to their accumulation in the ecosystem due to their highly stable and non-biodegradation nature. Photodegradation of four most consumed antibiotics such as amoxicillin, azithromycin, cefixime, and ciprofloxacin were studied using Cu₂O-TiO₂ nanotubes. Cytotoxicity evaluation of the native and transformed products was conducted on the RAW 264.7 cell lines. Photocatalyst loading (0.1-2.0 g/L), pH (5, 7 and 9), initial antibiotic load (50-1000 μg/mL) and cuprous oxide percentage (5, 10 and 20) were optimized for efficient photodegradation of antibiotics. Quenching experiments to evaluate the mechanism of photodegradation with hydroxyl and superoxide radicals were found the most reactive species of the selected antibiotics. Complete degradation of selected antibiotics was achieved in 90 min with 1.5 g/L of 10% Cu₂O-TiO₂ nanotubes with initial antibiotic concentration (100 μg/mL) at neutral pH of water matrix. The photocatalyst showed high chemical stability and reusability up to five consecutive cycles. Zeta potential studies confirms the high stability and activity of 10% C-TAC (Cuprous oxide doped Titanium dioxide nanotubes for Applied Catalysis) in the tested pH conditions. Photoluminescence and Electrochemical Impedance Spectroscopy data speculates that 10% C-TAC photocatalyst have efficient photoexcitation in the visible light for photodegradation of antibiotics samples. Inhibitory concentration (IC₅₀) interpretation from the toxicity analysis of native antibiotics concluded that ciprofloxacin was the most toxic antibiotic among the selected antibiotics. Cytotoxicity percentage of transformed products showed r: -0.985, p: 0.01 (negative correlation) with the degradation percentage revealing the efficient degradation of selected antibiotics with no toxic by-products.

Keywords: Antimicrobial resistance; Cu(2)O–TiO(2) nanotubes; Cytotoxicity; Photodegradation; RAW 264.7 cell lines.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Anti-Bacterial Agents* / toxicity
Catalysis
Ciprofloxacin / toxicity
Ecosystem
Light
Titanium / chemistry
Titanium / toxicity
Wastewater*

Substances

Anti-Bacterial Agents
titanium dioxide
cuprous oxide
Wastewater
Titanium
Ciprofloxacin