Photocatalytic degradation of gemifloxacin antibiotic using Zn-Co-LDH@biochar nanocomposite

Peyman Gholami; Alireza Khataee; Reza Darvishi Cheshmeh Soltani; Laleh Dinpazhoh; Amit Bhatnagar

doi:10.1016/j.jhazmat.2019.121070

Photocatalytic degradation of gemifloxacin antibiotic using Zn-Co-LDH@biochar nanocomposite

J Hazard Mater. 2020 Jan 15:382:121070. doi: 10.1016/j.jhazmat.2019.121070. Epub 2019 Aug 21.

Authors

Peyman Gholami¹, Alireza Khataee², Reza Darvishi Cheshmeh Soltani³, Laleh Dinpazhoh⁴, Amit Bhatnagar⁵

Affiliations

¹ Research Laboratory of Advanced Water and Wastewater Treatment Processes, Department of Applied Chemistry, Faculty of Chemistry, University of Tabriz, 51666-16471, Tabriz, Iran; Department of Environmental and Biological Sciences, University of Eastern Finland, P.O. Box 1627, FI-70211, Kuopio, Finland.
² Research Laboratory of Advanced Water and Wastewater Treatment Processes, Department of Applied Chemistry, Faculty of Chemistry, University of Tabriz, 51666-16471, Tabriz, Iran; Health Promotion Research Center, Iran University of Medical Sciences, 1449614535, Tehran, Iran; Department of Environmental Engineering, Gebze Technical University, 41400, Gebze, Turkey. Electronic address: a_khataee@tabrizu.ac.ir.
³ Department of Environmental Health Engineering, School of Health, Arak University of Medical Sciences, 38196-93345, Arak, Iran.
⁴ Research Laboratory of Advanced Water and Wastewater Treatment Processes, Department of Applied Chemistry, Faculty of Chemistry, University of Tabriz, 51666-16471, Tabriz, Iran.
⁵ Department of Environmental and Biological Sciences, University of Eastern Finland, P.O. Box 1627, FI-70211, Kuopio, Finland. Electronic address: amit.bhatnagar@uef.fi.

PMID: 31470301
DOI: 10.1016/j.jhazmat.2019.121070

Abstract

The aim of the present study was to investigate the photocatalytic performance of biochar (BC)-incorporated Zn-Co-layered double hydroxide (LDH) nanostructures in gemifloxacin (GMF) degradation as a model pharmaceutical pollutant. The as-prepared Zn-Co-LDH@BC showed high photocatalytic efficiency due to the enhanced separation of photo-generated charge carriers using cobalt hydroxide as well as inhibiting the agglomeration of LDH nanostructures by incorporation of BC. According to the results, 92.7% of GMF was degraded through photocatalysis in the presence of Zn-Co-LDH catalyst. The photocatalytic performance of BC-incorporated Zn-Co-LDH was highly dependent on the solute concentration and photocatalyst dosage. The addition of ethanol caused more inhibiting effect than that of benzoquinone (BQ), indicating the major role of ^•OH in decomposition of GMF compared to the negligible role of O₂^•-. A greater enhancement in the photocatalytic degradation of GMF was obtained when the photoreactor containing Zn-Co-LDH@BC nanostructures was oxygenated. Less than 10% drop in the removal efficiency of GMF was observed within five successive operational runs. The results of chemical oxygen demand (COD) analysis indicated the COD removal efficiency of about 80% within 200 min, indicating the acceptable mineralization of GMF. The reaction pathways were also proposed for the photocatalytic conversion of GMF under UV light irradiation.

Keywords: Antibiotic; Biochar; Layered double hydroxide; Photocatalysis; Ultraviolet light.

Publication types

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

MeSH terms

Anti-Bacterial Agents / chemistry*
Catalysis
Charcoal / chemistry*
Charcoal / radiation effects
Cobalt / chemistry*
Cobalt / radiation effects
Gemifloxacin / chemistry*
Hydroxides / chemistry*
Hydroxides / radiation effects
Nanocomposites / chemistry*
Nanocomposites / radiation effects
Photochemical Processes
Ultraviolet Rays
Zinc / chemistry*
Zinc / radiation effects

Substances

Anti-Bacterial Agents
Hydroxides
biochar
Charcoal
Cobalt
Zinc
Gemifloxacin