Sunlight-driven advanced oxidation process has promising applications and is increasingly receiving attention for the removal of emerging pollutants. This study describes a concentrated solar energy-driven photothermal (CSEP) system for the efficient degradation of fluoroquinolone antibiotics in wastewater. The operation of concentrating light degradation was not only a simple combination of thermal degradation and sunlight degradation, but the complex photothermal synergies that occurred to achieve degrading fluoroquinolones (FQs) more thoroughly. In the degradation processes, singlet oxygen (1O2), superoxide anion (O2·−), and hydroxyl radical (·OH) play pivotal roles. Additionally, the CSEP system exhibits outstanding defluorination capability (e.g., achieving 100 % defluorination for ciprofloxacin (CIP)). The photodegradation pathways of CIP were investigated using liquid chromatography/tandem mass spectrometry (LC/MS/MS), ion chromatography (IC) analysis, and density functional theory (DFT). Additionally, the aquatic ecological toxicity of CIP was assessed through ecological structure–activity relationship (ECOSAR) modeling and antimicrobial activity testing. Furthermore, this system demonstrates strong adaptability in addressing various natural water bodies, achieving an average degradation rate of over 98.00 % within a short time (3 min, 2 mg·L−1 CIP). In addition, it enhances the potential for synergistic removal of algae and degradation of FQs in complex water ecosystems. The adoption of this CSEP system holds considerable promise in furnishing robust technical support for the treatment and removal of FQs in water and wastewater.
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