CETMIC   05378
CENTRO DE TECNOLOGIA DE RECURSOS MINERALES Y CERAMICA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Caracterización y evaluacion de organoarcillas para la desorcion controlada de clorpirifos.
Autor/es:
M. PANTANETTI; M. DOS SANTOS AFONSO; R.M. TORRES SANCHEZ
Lugar:
Cacún
Reunión:
Congreso; VI Cong. Iberoamericano de Fisica y Quim.; 2011
Institución organizadora:
Soc. Iberoamericana de fisico y Quimica
Resumen:
The importance of understanding the interactions of agrochemicals in the soil, particularly with the insecticide Chlorpyrifos (CPF), is motivated by its wide application in crops, besides the global need to increase food production. Montmorillonite clays show significant adsorption capacity in the interlayer spacing, which may be modified by treatment with salts of quaternary amines to produce organoclays. The aim of this work was to obtain and characterize two organoclays (with octa decyltrimethylammonium (CO) bromide and phenyl trimethylammonium (CF) chloride) and the raw clay (C) and to evaluate the CPF desorption in order to further application such as slow-release formulations. Both organoclays showed a decrease of specific surface and apparent diameter, respect to C, indicating a formation increase of aggregates. While, only CO sample showed inversion to positive of the surface charge, the XRD spectra of the reflexion peak (001) indicated interlayer entrance of both quaternary amines and similar changes in the morphology were found for both organoclays. Samples with CPF adsorbed showed an interlayer increase of 3Å for C sample while little or none increase was found for both organoclays, indicating little CPF entrance in the interlayer surface. The zeta potential curves of samples with CPF indicated an increase and a decrease of negative charge for both organoclays and C samples respect to same samples without CPF. Both organoclays showed an first step (up to 25-50 h) of increasing desorption, attaining at 100-150 h only 0, 1,34 y 2,1 % for CO, C and CF, respectively.