Inactivation of Ascaris eggs in water using hydrogen peroxide and a Fenton type nanocatalyst (FeOx/C) synthesized by a novel hybrid production process

Inactivation tests of Ascaris eggs (Ae) were performed using hydrogen peroxide and a Fenton type nanocatalyst supported on activated carbon (AC) (FeOx/C). Blank inactivation tests were also carried out using H₂O₂ and H₂O₂/AC as oxidation systems. The FeOx/C nanocatalyst was synthesized through a novel hybrid method developed in this work. The method is based on the incipient impregnation technique, using isopropyl alcohol as dissolvent and chelating agent of the iron salt and the ultrasonic method. The supported nanocatalyst contained 2.61% w/w of total iron and the support 0.2% w/w. Transmission electron microscopy (TEM)–energy dispersive spectrometer (EDS) images permitted verification of the presence of finely dispersed FeOx nanoparticles, with sizes ranging from 19 to 63 nm. SEM–EDS analysis and TEM images also showed good dispersion of iron oxide nanoparticles, most probably maghemite; γ-Fe₂O₃, able to produce hydroperoxyl radical as reported in the literature. The FeOx/C nanocatalyst-H₂O₂ system showed an average Ae inactivation efficiency of 4.46% Ae/mg H₂O₂. This value is significantly higher than the result obtained using the support-H₂O₂ system and H₂O₂ alone and it is also better than data reported for the classical Fenton process (homogeneous phase) with or without UV light.