Combination of fenton-like-oxidation and photo-fenton in levofloxacin degradation using iron loaded in porous carbon

Abstract

The presence of antibiotics in wastewater has become a global concern due to the detrimental effects on human health and aquatic environments. This study aims to investigate the removal of levofloxacin by the Advanced Oxidation Process (AOP) in a heterogeneous system of iron-loaded porous carbon from sugar palm fiber (Fe/SPF-C). Sugar palm fiber, a byproduct of the starch industry, is an abundant precursor for the production of porous carbon. Porous carbon was prepared through pyrolysis and followed by an activation process using gaseous CO₂. Iron oxide was then loaded onto porous carbon by wet impregnation at various %-wt loadings. Several characterizations of N₂-sorption, SEM–EDX, and FTIR were used to reveal the properties of the catalyst, such as specific surface area, pore distribution, morphological structures, iron oxide distribution, and functional groups. The results showed that increasing the Fe loading to 6% did not significantly alter the catalyst structure or pore distribution. The adsorption of levofloxacin showed the best fit with the Langmuir isotherm and the pseudo-second-order kinetic model, with a maximum adsorption capacity of 39.8 mg/g. The photo-Fenton-like oxidation system demonstrates enhanced removal efficiency and catalyst reusability under optimal conditions: catalyst dosage of 0.2 g/L, H₂O₂ concentration of 120 mM, pH 7, and a reaction time of 3 h. The degradation efficiency using the photo-Fenton-like oxidation system reached 92.3 ± 3.5% with a reaction rate of 1.03 ± 0.04 s⁻¹, and the catalyst could be used up to 5 cycles. Catalyst of Fe/SPF-C 4% exhibited the best performance on levofloxacin removal.