Optimization of Solar Corrosion Fenton Reactor for the Recovery of Textile Wastewater: In Situ Release of Fe2+

A Solar Corrosion Fenton reactor (SCFr) was developed by packing an iron-carbon steel filament inside the reactor to enable the in situ release of Fe2+. A Box–Behnken experimental design was used to optimize the effect of HRT (20, 30, and 40 min), the mass ratios of the packed filament inside the reactor with respect to volume (0.1, 0.2, 0.3 w/v), and the peroxide dosage added (500, 1000, and 1500 mg/L), the response variables were the percentage removal of COD, color, and turbidity. The optimum conditions for SCFr were an HRT of 24.5 min, a ratio of 0.16 (0.0032 m2/L), and a peroxide dose of 1006.9 mg/L. The removal was 91.8%, 98.4%, and 87.3% COD, color, and turbidity, respectively. Without solar radiation, the percentage removal was reduced by 16.3%, 47.9%, and 34.0% in terms of COD, color, and turbidity, respectively. The concentration of Fe2+ released was 25.4 mg/L of Fe2+. Prolonged HRT increases Fe2+ concentration and turbidity, which increase COD. The oxidation kinetics were fitted to a Behnajady–Modirshahla–Ghanbery (BMG) model, which indicated a high oxidation rate that is reflective of low treatment times. The w/v ratio was the most significant factor; the release of Fe2+ was stimulated by UV radiation and the chloride concentration of wastewater, which prevents the formation of an oxide layer, thus allowing its continuous release, taking advantage of solar radiation and the pH and chloride concentration of the raw sample.