Optical Sensing of Nitrogen, Phosphorus and Potassium: A Spectrophotometrical Approach toward Smart Nutrient Deployment

• Tipo: Artigo em Revista Científica Internacional
• Data: 2019

Autores

Monteiro Silva, F (Autor) FCUP; Jorge, PAS (Autor) FCUP; Martins, RC (Autor) Outra

Revista

A Revista está pendente de validação pelos Serviços Administrativos.

Título: Chemosensors

Vol. 7

Página Final: 51

ISSN: 2227-9040

Indexação

ISI Web of Knowledge - 19 Citações

Scopus - 22 Citações

Outras Informações

ID Authenticus: P-00R-CHT

DOI: 10.3390/chemosensors7040051

Abstract (EN): The feasibility of a compact, modular sensing system able to quantify the presence of nitrogen, phosphorus and potassium (NPK) in nutrient-containing fertilizer water was investigated. Direct UV-Vis spectroscopy combined with optical fibers were employed to design modular compact sensing systems able to record absorption spectra of nutrient solutions resulting from local producer samples. N, P, and K spectral interference was studied by mixtures of commercial fertilizer solutions to simulate real conditions in hydroponic productions. This study demonstrates that the use of bands for the quantification of nitrogen with linear or logarithmic regression models does not produce analytical grade calibrations. Furthermore, multivariate regression models, i.e., Partial Least Squares (PLS), which consider specimens interference, perform poorly for low absorbance nutrients. The high interference present in the spectra has proven to be solved by an innovative self-learning artificial intelligence algorithm that is able to find interference modes among a spectral database to produce consistent predictions. By correctly modeling the existing interferences, analytical grade quantification of N, P, and K has proven feasible. The results of this work open the possibility of real-time NPK monitoring in Micro-Irrigation Systems.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 16