The leather industry produces a large quantity of solid waste (wet blue leather), which contains a high amount of chromium. After its removal from wet blue leather, a solid collagenic material is recovered, containing high nitrogen levels, which can be used as a nitrogen source in agriculture. In order to take more advantage of the collagen, it was enriched with mineral P and K in order to produce NPK formulations. The objective was also to evaluate the efficiency of such formulations as a nutrient supply for rice plants in an Oxisoil, under greenhouse conditions. The application of PK enriched-collagen formulations resulted in N contents in the vegetative parts and grains of rice plants which were equivalent or superior to those obtained with urea and commercial NPK formulations. © 2010 Elsevier B.V.
Nogueira, F. G. E., Castro, I. A., Bastos, A. R. R., Souza, G. A., de Carvalho, J. G., & Oliveira, L. C. A. (2011). Recycling of solid waste rich in organic nitrogen from leather industry: Mineral nutrition of rice plants. Journal of Hazardous Materials, 186(2–3), 1064–1069. https://doi.org/10.1016/j.jhazmat.2010.11.111