Efficient degradation of bisphenol from aqueous solutions via a Fenton-like process using C-ZIF-8@Fe/REEs catalysts

In this study, a novel C-ZIF-8@Fe/REEs composite, fabricated from one-step pyrolysis using ZIF-8@Fe adsorbed with rare earth elements (REEs) as precursors was successfully used to activate peroxymonosulfate (PMS) for efficient oxidation of Bisphenol A (BPA). The as-prepared C-ZIF-8@Fe/REEs exhibited high PMS activation performance, with an BPA removal efficiency exceeding 95 % within 120 min. Characterizations revealed that the REEs introduction increased the exposure of active sites, and facilitates the electron transfer. Electron paramagnetic resonance analysis and quenching tests confirmed that both radical (·OH, ·SO 4 − ) and non-radical ( 1 O 2 , high-valent metals, and electron transfer) pathways were involved in BPA degradation. Reasonable BPA degradation pathways were proposed by analyzing the results of LC-MS and DFT calculations. Additionally, toxicity assessments demonstrated a significant reduction in the toxicity of degradation products. Finally, the synthesized composite exhibited excellent reusability and stability in real wastewater fixed column bed experiments, with the removal efficiency still be higher than 70 % after 11 h operation. These findings demonstrate that the recovery REEs from mining wastewater is an effective strategy in developing a highly efficient Fenton-like catalysts, and also highlight the promising role of using C-ZIF-8@Fe/REEs in wastewater treatment, particularly for the removal of organic contaminants.