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-Fe2O3/TiO2 type II heterojunctions is reported. The photoreaction of the model solution was evaluated under UVA-visible irradiation with different amounts of α-Fe2O3 over TiO2, lactose as pollutant concentrations, Cl− and SO42− anions effects, and oxidant ambient showing up to 42% lactose degradation without the addition of oxidant ambient. Optimized parameters (1.0%wt α-Fe2O3/TiO2, [catalyst] = 0.5 g L−1, [lactose] = 0.7 g L−1, [H2O2] = 10 mM, [O2] = 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).