Iron(III) complex as a Fenton-like catalyst for wastewater treatment at near-neutral pH: catalytic performance and reusability

Abstract Conventional Fenton processes are effective for degrading recalcitrant contaminants; however, they are hindered by their requirement for strongly acidic conditions and the generation of large amounts of iron-containing sludge. To overcome these limitations, an iron(III) Schiff base complex (FeL) was synthesized, characterized, and evaluated as a Fenton-like catalyst active at near-neutral pH for the degradation of a model organic contaminant, Drimaren Red X-6BN (DRX-6BN), under dark conditions. The reaction parameters were systematically examined, and the degradation kinetics were interpreted using the Behnajady–Modirshahla–Ghanbery model. Under the best conditions (pH ~6.0, 1.17 × 10 –2 mol L −1 H 2 O 2 , 0.21–0.28 g L −1 FeL), approximately 85% removal was achieved without photoactivation. The catalyst retained 68% efficiency after seven consecutive cycles, indicating its capacity for reuse under oxidative conditions. Possible degradation pathways were discussed, and the performance was benchmarked against related Fenton-like systems, demonstrating competitive activity under milder operational conditions. These findings highlight the potential of FeL as a promising catalyst for Fenton-like oxidation under mild pH conditions, providing a basis for further investigations toward wastewater treatment applications.