Establishing an affordable solar-floating FeO@AR-TiO photo-Fenton catalytic system through the cyclic utilization of iron waste to de-pollute textile water contamination.

This study focuses on developing a cost-effective FeO catalyst from oilfield iron waste to create a floating heterogeneous photo-Fenton system with anatase/rutile(A/R) TiO heterophase photocatalyst (cork-FeO@AR-TiO) for treating textile pollution in sunlight. Through controlling sol-gel (SG) microwave heating technique, the A/R ratio of AR-TiO crystal is tuned (A/R ratio = 1.13 and E = 3.02 eV) to improve adsorption-photocatalytic removal of anionic/cationic dyes with an apparent kinetic rate (k) of 0.0074 min under UV-visible irradiation. The developed cork-FeO@AR-TiO floated system also outperforms the classical photo-Fenton with Fe/HO benchmark, showing a 2-fold enhancement in textile dye degradation (k = 0.216 min and space-time yield (SY) of 1.7*10 mol/E.g at pH 5.65) with high stability over four reuse cycles. The formation of FeO@AR-TiO Type-II heterojunction is confirmed by optical and electrochemical analyses, allowing the acceleration of direct electron transfer mechanism and oxidative degradation of dyes during photo-Fenton reaction. As a case study, the cork-FeO@AR-TiO system demonstrates a high capability for efficient mineralization of textile pollution in a real effluent, achieving 82 ± 2% reduction in the total organic contents at an operational cost of 2.61 $/kg.m in sunlight. Thus, this research addresses challenges in conventional Fenton chemistry, iron waste recycling, and catalyst retention, offering new insights for sustainable treatment of textile effluents and environmental protection.