Phosphorus Release from Nano-Hydroxyapatite Derived from Biowastes in the Presence of Phosphate-Solubilizing Bacteria: A Soil Column Experiment
Laura Pilotto, Francesca Scalera, Clara Piccirillo, Luca Marchiol, Mônica Yorlady Alzate Zuluaga, Youry Pii, Stefano Cesco, Marcello Civilini, Guido Fellet
Abstract
High Resolution Image Download MS PowerPoint Slide Phosphorus applications in agriculture can lead to significant environmental impacts, necessitating a revolution in current agricultural practices. This study explores the potential of hydroxyapatite nanoparticles (nHAPs) synthesized from poultry bones as P fertilizers. nHAPs were produced at 300 °C (nHAP 300 ) and 700 °C (nHAP 700 ), and their effectiveness was evaluated. An in vitro solubilization test with Pseudomonas alloputida evaluated the bacterium’s ability to solubilize the nanoparticles, assessing dissolved P and organic acids produced. Additionally, a soil leaching test measured P losses and bioavailable P in soil compared to a conventional fertilizer, the triple superphosphate (TSP). nHAP 300 displayed heterogeneous sizes, while nHAP 700 were approximately 100 nm in size, with a P content of 8.8% and 19.4%, respectively. Pseudomonas alloputida successfully solubilized both types of nanoparticles, with nHAP 700 demonstrating a higher solubility than nHAP 300 . The TSP treatment resulted in higher P losses (6.35 mg) compared with nHAP treatments (nHAP 300 0.32 mg; nHAP 700 0.28 mg), indicating the potential of nHAP for recycling P from waste. Our findings indicate that nHAP 700 are more efficient in P release than nHAP 300 but less prone to leaching compared to conventional fertilizers. Utilizing these nanoparticles enables phosphorus recovery from waste and holds significant potential for sustainable agricultural applications.