A comprehensive review on impregnated magnetic nanoparticle in advanced wastewater treatment: An in-depth technical review and future directions

Advanced wastewater treatment technologies are required to address the global water pollution crisis, and ferrous nanoparticles (FeNPs) have emerged as a promising solution because of their high surface area (>100 m2/g), tunable functionalities, and magnetic properties. Effective pollutant removal is made possible by FeNPs, which are synthesized using techniques like co-precipitation and sol-gel and typically range in size from 10 to 100 nm. Functionalization with organic ligands, silica, or polymers improves their stability and selectivity. With adsorption capacities of up to 500 mg/g, FeNPs show remarkable effectiveness in eliminating organic contaminants (like dyes and medications), heavy metals (like Pb2 + and Cd2+) with > 90 % efficiency, and emerging pollutants (like microplastics). Even at low concentrations (1–10 mg/L), magnetic separation achieves > 95 % recovery efficiency by taking advantage of FeNPs' high susceptibility (10–100 emu/g). The study's novelty explores the advanced functionalization of FeNP-based systems that are environmentally sustainable, using 20–30 % less energy than traditional methods, and economically feasible, with synthesis costs ranging from $50 to $200/kg. Because of their reusability (up to 10 cycles), FeNPs are a scalable and effective solution to the world's water pollution problems, further reducing waste.