INFLUENCE OF INORGANIC PHOSPHORUS AND PH VALUE ON THE REMOVAL OF AQUEOUS ENVIRONMENT GLYPHOSATE-BASED FORMULATION BY ADSORPTION

• Autor(a) principal: Cuba, Renata Medici Frayne
• Data de Publicação: 2020
• Outros Autores: Paiva, Débora Cristina Aguiar Chaves, Cintra, Túlio Salatiel, Terán, Francisco Javier Cuba
• Tipo de documento: Artigo
• Idioma: por
• Título da fonte: Revista Brasileira de Ciências Ambientais (Online)
• Texto Completo: https://www.rbciamb.com.br/Publicacoes_RBCIAMB/article/view/557
• topic: Herbicida. Nutrientes. Adsorção competitiva.; Herbicide. Nutrients Competitive adsorption.

Water resources degradation due to atrophic activities has depleted thephysical-chemical characteristics of surface waters, interfering in the mobilityof the compounds that are capable of settling on sediments. This work assessedthe effect of phosphorous concentration and pH value on kinetics and adsorptioncapacity of glyphosate (commercial solution) in expanded clay, using a bench scale system composed by a batch-operated fixed-bed column reactor with internal recirculation of adsorbate. An experimental planning model was used for three phosphorous concentrations, 0.8, 8 and 16 mg.L-1 as well as three pH values of 4, 7 and 10, totaling 9 tests. It was verified that the increase in pH and phosphorousconcentration led to a decrease in adsorption velocity, while the kineticalmechanism was affected just by phosphorous concentration, prevailing a pseudosecondorder mechanism for concentrations of 0.8 and 8 mg.L-1, and a intraparticlemechanism for the highest concentration. The adsorption capacity was affectedby both parameters. For each increment of 0.16 in pH value and 0.22 mg.L-1 inphosphorous concentration, the adsorbed mass of glyphosate decreased by0.000385 and 0.000205 mg.g-1, respectively. Thus, it was concluded that theincrease in pH and phosphorous concentration decreased both the capacityand speed of glyphosate adsorption (commercial formulation), while the kineticmechanism was only altered for phosphorous concentration of 16 mg.L-1.