In recent years, antibiotic residues are commonly detected in a variety of water bodies, causing serious threat to water ecosystems and human health. The removal of antibiotic contaminants from water based on the advanced oxidation process of activated persulfate has become a hot research topic due to its strong oxidative properties, high selectivity, and wide pH applicability range. Iron-based bimetallic materials with low cost, high stability, and excellent catalytic performance can effectively activate persulfate, which makes up for the defects of being a single iron activator, such as easy deactivation, low efficiency, and producing secondary pollution easily. Three typical Fe-based bimetallic catalysts, namely spinel ferrite, Fe-based layered double hydroxides, and Fe-based Prussian blue analogues, were investigated and analyzed for their activation of persulfate for antibiotic degradation. Several intrinsic mechanisms of persulfate activation by Fe-based bimetallic catalysts are systematically discussed, including the generation of free radicals, singlet oxygen, and high-valent metals; the process of electron transfer; and the direct oxidation process of persulfate. Finally, the general degradation pathways of four typical antibiotics, including fluoroquinolones, sulfonamides, tetracyclines, and β-lactam antibiotics, are summarized to act as a reference for future studies on the application of Fe-based bimetallic catalysts and their modifications, derivatives, and complexes in the activating technology of persulfate.
Keywords: bimetallic; degradation pathways; driving mechanism; iron-based; persulfate.