Facile synthesis of carbon doped CoAl-LDH for peroxymonosulfate activation and antibiotic degradation: Pilot scale and hospital wastewater application

Levofloxacin (LFX), a widely used antibiotic, exhibits high chemical stability and resistance to conventional wastewater treatment methods, posing serious environmental and health concerns. In this study, a super-capacitor activated carbon (SAC) doped with flower-like CoAl-layered double hydroxide (LDH) was synthesized via a one-step hydrothermal method through a doping strategy. The SAC-LDH composite demonstrated superior performance in activating peroxymonosulfate (PMS, 0.12 mM) achieving 95 % degradation efficiency of LFX (10 mg/L) within 5 min. The high specific surface area and excellent adsorption capacity of SAC facilitated effective accumulation of LFX on the catalyst surface, enhancing reaction kinetics. The rapid conversion of Co 2 + and Co 3+ in the catalyst was suggested to generate highly reactive oxygen species, including SO 4 •- , •OH, O 2 •- , and 1 O 2 . This process was further demonstrated by electron paramagnetic resonance (EPR), in-situ Raman spectroscopy, Fourier transform infrared spectroscopy (FT-IR), and X-ray photo-electron spectroscopy (XPS). Pilot-scale fixed-bed reactor testing of SAC-LDH for pre-treated hospital wastewater treatment (soluble chemical oxygen demand (SCOD) > 140 mg/L) was conducted. The system exhibited long-term stability, anti-interference ability, and high catalytic efficiency under continuous flow condition (1.0 L/h, 7 days). These findings highlight the developed composite SAC-LDH + PMS system as a highly efficient, stable, and scalable solution for treating antibiotic-contaminated wastewater treatment, offering strong potential for real-world environmental remediation application.