Amino-modified metal–organic frameworks as peroxymonosulfate catalyst for bisphenol AF decontamination: ROS generation, degradation pathways, and toxicity evaluation

Abstract

Advanced oxidation processes (AOPs) based on the metal–organic frameworks (MOFs) and peroxymonosulfate (PMS) have been demonstrated as promising methods for the degradation of contaminants. In this study, the degradation of bisphenol AF (BPAF) by activated PMS via amino-modified metal–organic frameworks (AMOF) was investigated thoroughly. BPAF could be efficiently removed (94.1%) in the optimal condition. The decontamination of BPAF could be accelerated significantly with the increasing temperature, and a highly stable degradation performance was observed at a wide pH range. Quenching experiments and electron paramagnetic resonance (EPR) tests revealed that sulfate radical (SO4–•), hydroxyl radical (HO•), singlet oxygen (1O2), and superoxide radical (O2–•) were produced synergistically in the AMOF/PMS system. Chloride ion (Cl–) exhibited a dual influence on BPAF removal, while other anions and NOM could hinder the degradation rate mildly. A total of fifty-two intermediates were identified using UHPLC-MS/MS method and four main degradation pathways were proposed based on the density functional theory (DFT) calculation, including the frontier molecular orbital theory (FMO), natural population analysis (NPA), and Fukui function. Finally, the Quantitative Structure Activity Relationship (QSAR) method for Toxicity Estimation Software Tool (TEST) was applied to estimate the accurate toxicity of BPAF and degradation byproducts. This study exhibited the promising potential for the decontamination of BPAF in the water via the AMOF based AOPs.