Fe–TiO<sub>2</sub> Composite Mediated the Hybrid Effect of Photocatalysis and Photo-Fenton for the Inactivation of <i>Escherichia coli</i> Using a Continuous Flow Recirculation Reactor
Ina Thakur, Anoop Verma, Banu Örmeci
Abstract
To reduce the harmful effects of bacteria, the low-cost and visibly active Fe–TiO2 composite was prepared to remove Escherichia coli from water using a continuous recirculating reactor. The performance of the hybrid process (Fe–TiO2) was evaluated in terms of reaction rate constant, quantum yield, and some other operating parameters. This hybrid process showed a significant increase in reaction rate constant and quantum yield (0.065 min–1 and 0.077 × 10–15 cells/photons, respectively) compared to photo-Fenton (0.029 min–1 and 7.57 × 10–15 cells/photons, respectively) and photocatalysis (0.025 min–1 and 11.96 × 10–15 cells/photons, respectively) in 150 min treatment time. The p-value was less than 0.0001, and the F-value was greater than 5 for each process. The optimized values of the operating parameters were found to be 3.4, 62 mg L–1, 106 mL min–1 for the reaction pH, H2O2 concentration, and flow rate, respectively. With these optimum conditions, a percentage reduction of E. coli of 93% was observed. The Fe–TiO2 composites exhibited high stability under continuous flow conditions, demonstrating their long-term durability. The results of this study demonstrate the potential of waste materials as a promising concept for the post-treatment of wastewater that can be successfully applied in real life.