Degradation of dairy wastewater using sustainable nanotechnology composed of a‐Fe2O3/TiO2 rod‐shaped material and photocatalytic process: a complementary treatment approach for industrial wastewater

Abstract BACKGROUND High water consumption and the toxic pollutants found in industrial wastewater are key challenges in achieving a more sustainable development. In this sense, it is crucial to develop sustainable ways to reduce the organic pollutants found in wastewater and to promote its reuse. RESULTS In this study, a simple, low‐cost, and environmentally friendly path for dairy wastewater decontamination through photocatalysis using rod‐shaped α‐Fe 2 O 3 /TiO 2 type II heterojunctions is reported. The photoreaction of the model solution was evaluated under UVA‐visible irradiation with different amounts of α‐Fe 2 O 3 over TiO 2 , lactose as pollutant concentrations, Cl − and SO 4 2− anions effects, and oxidant ambient showing up to 42% lactose degradation without the addition of oxidant ambient. Optimized parameters (1.0%wt α‐Fe 2 O 3 /TiO 2 , [catalyst] = 0.5 g L −1 , [lactose] = 0.7 g L −1 , [H 2 O 2 ] = 10 mM, [O 2 ] = constant) were used on dairy wastewater, which showed a 63% total organic carbon reduction and a 56% chemical oxygen demand reduction. The composite was easily recovered by decantation with a turbidity reduction of ~ 99%. The photocatalyst reusability was assessed over three successive uses and it maintained its activity with a loss of only 10%. CONCLUSION This study offers a promising approach for the development of innovative sustainable nanotechnology to efficiently degrade organic pollutants commonly found in dairy wastewater and improve its quality within a shorter timeframe. Our approach could contribute to the development of efficient and cost‐effective complementary technologies for the Sequencing Batch Reactor in the treatment of dairy wastewater, thus contributing to the sustainability of the dairy industry. © 2024 Society of Chemical Industry (SCI).