Environmentally-friendly rGO/Mn nanocomposites for efficient removal of tetracycline and its degradation pathway

Mei Lin; Miao Wang; Jianwang Wu; Ming Liu; Zuliang Chen

doi:10.1016/j.jenvman.2025.124269

Environmentally-friendly rGO/Mn nanocomposites for efficient removal of tetracycline and its degradation pathway

J Environ Manage. 2025 Jan 24:375:124269. doi: 10.1016/j.jenvman.2025.124269. Online ahead of print.

Authors

Mei Lin¹, Miao Wang¹, Jianwang Wu¹, Ming Liu¹, Zuliang Chen²

Affiliations

¹ Fujian Province Key Laboratory of Pollution Control and Resource Reuse, College of Environmental and Resource Science, Fujian Normal University, Fuzhou, 350007, Fujian Province, China.
² Fujian Province Key Laboratory of Pollution Control and Resource Reuse, College of Environmental and Resource Science, Fujian Normal University, Fuzhou, 350007, Fujian Province, China. Electronic address: zlchen@fjnu.edu.cn.

PMID: 39862825
DOI: 10.1016/j.jenvman.2025.124269

Abstract

Since the widespread use of antibiotics, the residues of antibiotics have frequently been detected in various water sources, making antibiotic pollution an urgent environmental issue. In this paper, one-step green synthetic reduced graphene/manganese nanoparticles (rGO/Mn NPs) composites have been utilized as a novel environmentally-friendly catalyst for tetracycline (TC) removal. The results demonstrated that rGO/Mn NPs exhibit excellent adsorption performance for TC, and can efficiently activate sodium persulfate (PDS) to oxidize and degrade TC. Furthermore, the rGO/Mn NPs adsorption-oxidation system (85.2%) was more effective than the adsorption process (70.9%) in removing TC (50 mg L^-1). Free radical quenching experiments and EPR results elucidated that singlet oxygen (¹O₂) and superoxide radicals (·O₂^-) are the primary reactive species responsible for the degradation of TC in the oxidation system. Based on the characterization results, a mechanism of oxidative degradation of TC by rGO/Mn NPs has been proposed. To further elucidate the degradation pathway of TC, the degradation products were identified by high performance liquid chromatography-mass spectrometry (HPLC-MS). This analysis provides a foundation for understanding how the rGO/Mn NPs composites activate PDS to degrade TC. Additionally, the ecological structure-activity relationship analysis revealed that TC is converted into intermediates with lower toxicity.

Keywords: Adsorption-oxidation; Degradation pathway; Green synthesized; Tetracycline; rGO/Mn NPs.