Optimization of iron (III) oxide nanoparticles production from natural waste for use in wastewater applications

Abstract Research on environmentally friendly synthesis using natural waste materials has gained momentum due to the increasing demand for sustainable nanomaterials. This study proposes a green synthesis approach for Fe 2 O 3 nanoparticles using an extract from Golden Shower Flower as a natural stabilizing agent. The environmental impact of this bio-based synthesis is assessed through a Life Cycle Assessment (LCA) framework, following ISO 14040-44 standards, and is compared to conventional chemical methods. Key findings indicate that this approach significantly reduces environmental impact, including climate change potential (0.002022 kg CO 2 ), fossil depletion (3.17E-07 kg oil eq.), and human toxicity levels, making it a more sustainable alternative. However, potential environmental trade-offs exist due to the energy consumption required for extract preparation and purification. To further optimize the synthesis process, a response function model was developed using Central Composite Design (CCD), achieving a high R 2 value of 0.998, confirming strong predictive accuracy. A confirmatory experiment using optimized conditions – 0.03 M precursor concentration, 80.5 min of ultrasonication, and 550 °C calcination – resulted in the production of Fe 2 O 3 nanoparticles with an average size of approximately 15 nm. The synthesized Fe 2 O 3 nanoparticles exhibited excellent performance in wastewater treatment, offering a dual environmental benefit by reducing waste while improving water purification solutions. The uniform particle size distribution and magnetic properties reinforce the potential of waste-derived nanomaterials in driving sustainable nanotechnology. Additionally, they emphasize the importance of scalability, process optimization, and industrial integration in realizing a circular economy-driven approach.