Synthesis of magnetite particles for enhanced environmental performance: Comparative analysis of three schemes and their applications for phosphorus recovery from high-strength wastewater

This study employed a reverse coprecipitation method to synthesize magnetite particles, utilizing three distinct schemes based on varied starting materials: mill scale (Scheme 1), chloride salts of ferrous and ferric (Scheme 2), and sulfate salts of ferrous and ferric (Scheme 3). Characterization techniques, including XRD, confirmed the cubic spinel structure in all schemes. BET surface area results showed variations, with Scheme 1 at 95.46 m2/g, 2 /g, increasing to 150.82 m2/g 2 /g for Scheme 2 and 133.36 m2/g 2 /g for Scheme 3. FTIR and XPS analyses validated the functionalities and chemical composition, confirming purity. VSM results confirmed the ferromagnetic nature of particles synthesized using all three schemes, with Scheme 1 exhibiting superior coercivity. SEM images revealed that particles synthesized using Scheme 1 were larger compared to those in Schemes 2 and 3. Scheme 3 showed the highest level of particle agglomeration, while Scheme 2 exhibited the least. TEM analysis confirmed consistently shaped nanoparticles with a uniform size distribution. EXD analysis confirmed Fe and O as the main constituents. The particles demonstrated effectiveness in phosphorus adsorption, with Scheme 1 exhibiting superior yield, P-recovery, and regeneration. These findings offer valuable insights into magnetite particle synthesis for optimal environmental performance, particularly in phosphorus removal.