INFLUÊNCIA DO FÓSFORO INORGÂNICO E VALOR DE PH NA REMOÇÃO DE FORMULAÇÃO À BASE DE GLIFOSATO EM AMBIENTE AQUOSO POR ADSORÇÃO

Renata Medici Frayne Cuba; Débora Cristina Aguiar Chaves Paiva; Túlio Salatiel Cintra; Francisco Javier Cuba Terán

doi:10.5327/Z2176-947820200557

Authors

Renata Medici Frayne Cuba Universidade Federal de Goiás https://orcid.org/0000-0002-3455-8198
Débora Cristina Aguiar Chaves Paiva Universidade Federal de Goiás https://orcid.org/0000-0002-7209-9527
Túlio Salatiel Cintra Universidade Federal de Goiás https://orcid.org/0000-0002-1745-6114
Francisco Javier Cuba Terán Universidade Federal de Goiás https://orcid.org/0000-0001-7056-3093

DOI:

https://doi.org/10.5327/Z2176-947820200557

Keywords:

Herbicide. Nutrients Competitive adsorption.

Abstract

Water resources degradation due to atrophic activities has depleted the
physical-chemical characteristics of surface waters, interfering in the mobility
of the compounds that are capable of settling on sediments. This work assessed
the effect of phosphorous concentration and pH value on kinetics and adsorption
capacity 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 phosphorous
concentration led to a decrease in adsorption velocity, while the kinetical
mechanism was affected just by phosphorous concentration, prevailing a pseudosecond
order mechanism for concentrations of 0.8 and 8 mg.L-1, and a intraparticle
mechanism for the highest concentration. The adsorption capacity was affected
by both parameters. For each increment of 0.16 in pH value and 0.22 mg.L-1 in
phosphorous concentration, the adsorbed mass of glyphosate decreased by
0.000385 and 0.000205 mg.g-1, respectively. Thus, it was concluded that the
increase in pH and phosphorous concentration decreased both the capacity
and speed of glyphosate adsorption (commercial formulation), while the kinetic
mechanism was only altered for phosphorous concentration of 16 mg.L-1.

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Author Biographies

Renata Medici Frayne Cuba, Universidade Federal de Goiás

Bacharel em Química pelo Instituto de Química de São Carlos (IQSC) da Universidade de São Paulo (USP). Mestre e Dra. em Hidrúlica e Saneamento pela Escola de Engenharia de São Carlos (EESC) da Universiade de São Paulo (USP) ; Professora Adjunta da Escola de Engenharia Civil e Ambiental, (EECA) e do Programa de Pós-Graduação em Engenharia Ambiental e Sanitária (PPGEAS) da Universidade Federal de Goiás (UFG)

Débora Cristina Aguiar Chaves Paiva, Universidade Federal de Goiás

Mestre em Engenharia Ambiental e Sanitária pela Universidade Federal de Goiás (UFG); Especialista em Planejamento e Gestão Ambiental pela Universidade Federal de Goiás (UFG); Tecnóloga em Saneamento Ambiental pelo Instituto Federal de Goiás (IFG)

Túlio Salatiel Cintra, Universidade Federal de Goiás

Mestre em Engenharia de Recuros Hídricos e Ambiental pela Universidade Federal do Paraná (UFPR); Graduado em Engenharia Ambiental e Sanitária pela Universidade Federal de Goiás (UFG)

Francisco Javier Cuba Terán, Universidade Federal de Goiás

Engenheiro Civil; Mestre e Doutor em Hidráulica e Saneamento pela Universidade de São Paulo; Professor Adjunto da Escola de Engenharia Civil e Ambiental, (EECA) da Universidade Federal de Goiás (UFG)