Thermal solar Fenton reactor: degradation of Eosin Y dye catalyzed by Fe galvanic release and temperature evaluation by CFD simulation.

The aim and innovation of this research is to evaluate a Solar Thermal Galvanic Fenton System (STGF) for the aqueous solution treatment of Eosin Y dye (EYD), using a Fe catalyst from an Fe-Cu galvanic cell, where thermal energy is captured and supplied through a cylindrical parabolic concentrator (CPC). The optimal conditions were determined using a Box-Behnken experimental design; the effects of the dose of HO (100 mg/L, 200 mg/L, and 300 mg/L), Fe-Cu catalyst ratio (0.1, 0.2, and 0.3), and hydraulic retention time (HRT) (10 min, 20 min, and 30 min) were studied; the initial concentration of EYD was 50 mg/L. The response variables were the percentage removal of chemical oxygen demand (COD), turbidity, color (Pt-Co U), and EYD. At the optimal COD removal conditions (10 min HRT, 0.3 catalyst ratio, and 100 mg/L HO), the removal efficiencies were 93.52% COD, 96.88% turbidity, 88.75% color, and 97.13% dye at 61.8 °C. Under the same operating conditions, temperature has a significant effect on treatment, and the removal efficiencies were 0.0% COD, 2.5% turbidity, 1.3% color, and 6.4% dye at 19.5 °C. It was observed that temperature has a significant effect on treatment; this is because the Fenton reaction can be accelerated by increasing the temperature, which improves the generation rate of OH. Computational fluid dynamics (CFD) analysis indicated that the flow rates and velocity influenced the temperature distribution reached by the TSGF system; therefore, the HRT in the process operation had a significant effect on COD removal at higher temperatures and lower efficiencies. An increase in the temperature can improve the removal efficiency of persistent pollutants in Fenton reactions. The main advantages of the STGF system are sustainability, self-contained, inexpensive, and portable, which makes its operation easier in remote locations.