Blast furnace dust waste (BFDW) proved efficient as a photocatalyst for the decolorization of methylene blue (MB) dye in water. Structural analysis unequivocally identified α-Fe₂O₃ as the predominant phase, constituting approximately 92%, with a porous surface showcasing unique 10–30 nm agglomerated nanoparticles. Chemical and thermal analyses indicated surface-bound water and carbonate molecules, with the main phase’s thermal stability up to 900 °C. Electrical conductivity analysis revealed charge transfer resistance values of 616.4 Ω and electrode resistance of 47.8 Ω. The Mott-Schottky analysis identified α-Fe₂O₃ as an n-type semiconductor with a flat band potential of 0.181 V vs. Ag/AgCl and a donor density of 1.45 × 10¹⁵ cm⁻³. The 2.2 eV optical bandgap and luminescence stem from α-Fe₂O₃ and weak ferromagnetism arises from structural defects and surface effects. With a 74% photocatalytic efficiency, stable through three photodegradation cycles, BFDW outperforms comparable waste materials in MB degradation mediated by visible light. The elemental trapping experiment exposed hydroxyl radicals ($\mathrm{O}\mathrm{H}_{•}^{}$) and superoxide anions (${\mathrm{O}}_2^{-}_{•}^{}$) as the primary species in the photodegradation process. Consequently, iron oxide-based BFDW emerges as an environmentally friendly alternative for wastewater treatment, underscoring the pivotal role of its unique physical properties in the photocatalytic process.

The production of natural gas (NG) and its contribution to the world energy matrix have increased in recent years. The use of natural gas, mainly stranded gas, usually requires pretreatment. This paper presents a mathematical model for reactive absorption in a bubble column containing a sodium hydroxide solution to remove sour components from natural gas. Model validation was based on experimental data by solving the system of equations via the computer package EMSO-Environment for Modeling, Simulation and Optimization. The results of the evaluation for some operating situations demonstrate that the model can be considered a suitable tool for accurately simulating the removal of H₂S even in the presence of CO₂ and provides a means to control the process on the basis of easily measured process variables, which are appropriate for the desulfurization of natural gas from stranded gas reserves.