Abstract

VITTA BRITO, Yosmery; FERNANDEZ CUERVO, Alberto; MOLINER-MARTINEZ, Yolanda  and  CAMPINS FALCO, Pilar. Removal of organophosphorus pesticides in water with supported silica Fe₃O₄ magnetic nanoparticles. Rev. Fac. Ing. UCV [online]. 2014, vol.29, n.3, pp.65-71. ISSN 0798-4065.

This paper evaluates the efficiency of Fe₃O₄ magnetic nanoparticles embedded in silica matrix, by a sol-gel method, as adsorbent of two organophosphate pesticides, Chlorfenvifos (Chlorf) and Chlorpyrifos (Chlorp), in sewage. The Fe₃O₄- SiO₂ Nps have an average size of 5 nm. The detection limits were 1 μ g L^-1 for the Chlorf and 2 μ g L^-1 for the Chlorp, obtaining an intra-day precision of 2% and inter-day 3%. According to the Langmuir adsorption isotherm, the Chlorp was identified as the more adsorbed species with Smax = de 0.70 ± 0.15 μg g^-1, while Smax = 0.40 ± 0.12 μg g^-1 for Chlorf. The procedure was tested on sewage, reaching analyte’s removal between 60 - 85%. The adsorption mechanism of pesticides is attributed to the hydrophobic interaction between these compounds and aliphatic chains of CTAB micelles, since the percentage of compounds in the liquid was less than 10%.

Keywords : Nanoparticles; Remediation; Pesticides; Solid phase extraction; Adsorption.