Study on the photocatalytic degradation of ciprofloxacin in coiled flow inverter microreactor

To achieve efficient degradation of ciprofloxacin (CIP), this work investigates the performance of a TiO 2 slurry system within the coiled flow inverter microreactor (CFIMR). The CFIMR utilizes its unique structural properties to induce chaotic mixing, thereby enhancing photon utilization and reaction kinetics in a slurry-phase environment. We systematically explored the influence of key operational parameters on the degradation process, specifically examining single residence time, catalyst dosage, initial CIP concentration, illumination methods, pH, and matrix composition. Comprehensive evaluations were conducted regarding the efficacy, stability, and overall efficiency of the system. Results indicate that the 98.49% degradation rate was achieved for a 10 mg/L CIP solution with a cumulative residence time of only 30 s under optimal conditions. The process exhibited an initial apparent reaction rate constant ( k app0 ) of 0.1539 s -1 and a space-time yield (STY) of 2880 m 3 pollutant per m 3 reactor per day. Notably, the CFIMR demonstrated superior performance compared to conventional reactors, with k app0 and STY increasing by two and one orders of magnitude, respectively. Furthermore, compared to the straight spiral tube microreactor (SSTMR), the CFIMR improved photon efficiency by 5.9% while reducing electrical energy per order ( E EO ) by 20%. This work provides a solid theoretical foundation for applying CFIMR in slurry-based photocatalysis. Download: Download high-res image (207KB) Download: Download full-size image