One step hydrothermal synthesis of green Iron-Modified Catalyst by food waste biogas residue for Ozonation of Ciprofloxacin: Characterization, Degradation Mechanism, DFT study and Reactive Oxygen Species role
Description
Recently, Biogas has been a well-known energy source due to global energy crises and huge urban leftover food waste by hospitality or food delivery. Still, it produces untreated biogas residue (BR), which causes heavy metals, and hazardous compounds leaching. Additionally, the proliferation of antibiotics such as ciprofloxacin (CIP) in the dairy and veterinary industry results in continuous release into water, posing a serious threats to ecological health. Herein, this study presents the hydrothermal synthesis of a series of Iron (Fe)-modified catalysts derived from eco-friendly ball milling boosted biogas residual biochar (BRB) to remove CIP via catalytic ozonation degradation. Fe-modified biochar with 2.5 wt. % iron loading and synthesized at 240 ℃ (2.5Fe-FBRB-240 ℃) exhibited the highest removal efficiency of 98.61% and stability for ten cycles of 20 min each. An optimal catalyst has demonstrated potential for CIP degradation in river and tap water, and ICP-MS has shown safer Fe-leaching. Toxicity assessment, mechanism, and degradation pathways were also proposed. Electrochemical studies, density functional theory (DFT) calculations, and Electron paramagnetic resonance (EPR) analysis confirmed the involvement of electron transfer and reactive oxygen species, like hydroxyl radicals (•OH), sulfate radicals (SO4•−), and singlet oxygen (1O2) in CIP degradation. This study provides a novel perspective for eliminating organic contaminants using biogas residue biochar-based catalysts.