title: Incorporation of mineral phosphorus and potassium on leather waste (collagen): a new N(collagen)PK-fertilizer with slow liberation.
abstract: The feasibility of using a solid waste (rich in nitrogen) from the leather industry, after chromium extraction, as adsorbent for P and K, for possible utilization as NPK fertilizer was evaluated. The materials, with and without the addition of P and K, were characterized by chemical analyses, infrared spectroscopy, EDS (energy dispersive X-ray spectrometry) and SEM (scanning electronic microscopy). Langmuir and Freundlich equations were used for analyzing the experimental data, which showed a better fit to the Freundlich model, thus suggesting a multilayer adsorption process on the surface of the adsorbent. A preliminary test in greenhouse demonstrates that the P and K incorporation on the matrix rich in nitrogen (collagen) is a interesting alternative to use such material as NPK fertilizer. The application of N(collagen)PK formulations, as a source of nutrients for the growth of rice plants, showed promising agronomic results.
authors.affiliation: Departamento de Química, Universidade Federal de Lavras, Caixa Postal 3037, CEP 37200-000, Lavras-MG, Brazil.
authors.forename: Francisco G E
authors.initials: FG
authors.lastname: Nogueira
authors.forename: Nayara T
authors.initials: NT
authors.lastname: do Prado
authors.forename: Luiz C A
authors.initials: LC
authors.lastname: Oliveira
authors.forename: Ana R R
authors.initials: AR
authors.lastname: Bastos
authors.forename: João H
authors.initials: JH
authors.lastname: Lopes
authors.forename: Janice G
authors.initials: JG
authors.lastname: de Carvalho
mesh_terms: D003094:Collagen / Q000737:chemistry*; D003247:Conservation of Natural Resources / Q000379:methods*; D005308:Fertilizers; D008903:Minerals; D012275:Oryza / Q000187:drug effects / Q000254:growth & development; D010758:Phosphorus / Q000737:chemistry*; D011188:Potassium / Q000737:chemistry*
chemical_list: D005308:Fertilizers; D008903:Minerals; D010758:Phosphorus; D003094:Collagen; D011188:Potassium