An Environment‐Friendly Nanoparticle for Agricultural Purposes

The low efficiency and excessive application of traditional fertilizers cause eutrophication of water bodies. Nanofertilizers are promising alternatives to conventional fertilizers. The use of mining residues as a source of nutrients for agriculture emerges as a sustainable, ecologically friendly, and economically viable alternative once its potential has been tested. This study had as its aim to use acid mine drainage water as a source of iron to synthesize iron‐based oxide nanoparticles and evaluate the nutrient bioavailability for agricultural purposes. The iron was recovered from waste by a selective precipitating process, and the nanoparticles were composed predominantly of hematite and other minerals such as thenardite, blödite, and changoite. The synthesized particles release significant amounts of iron, calcium, magnesium, and phosphorus into the water, which suggests that the synthesized iron‐based oxide nanoparticles have high potential for use as nano‐fertilizers for agriculture. This strategy is crucial from an environmental point of view, as it involves recycling mining residues and promoting new uses in agriculture.