Browsing by Subject "4-chlorophenol removal"

Now showing 1 - 2 of 2
  • Thumbnail Image
    Publication
    Restricted
    Continuous tank reactors in series: an improved alternative in the removal of phenolic compounds with immobilized peroxidase
    (Taylor and Francis Group, Taylor and Francis, 2012-01-24) Gómez Gómez, Elisa; Máximo, María Fuensanta; Montiel Morte, María Claudia; Gómez Gómez, María; Murcia Almagro, María Dolores; Ortega Requena, Salvadora; Ingeniería Química; Facultad de Química
    Immobilized derivatives of soybean peroxidase, covalently bound to a glass support, were used in a continuous stirred tank reactor in series, in order to study the removal of two phenolic compounds: phenol and 4-chlorophenol. The use of two reactors in series, rather than one continuous tank, improved the removal efficiencies of phenol and 4-chlorophenol. The distribution of different amounts of enzyme between the two tanks showed that the relative distributions influenced the removal efficiency reached and the degree of the enzyme deactivation. The highest removal percentages were reached at the outlet of the second tank for a distribution of 50% of the enzyme in each tank. However, with a distribution of 75% in the first tank and 25% in the second, the elimination percentage in the second tank was slightly lower than in the previous case, and the effects of deactivation of the enzyme in the first tank were less pronounced. In all the distributions assayed it was observed that the first tank acts as a filter for the second one, which receives a feed with a smaller load of phenolic compounds, thus diminishing enzyme deactivation in the second tank.
  • Thumbnail Image
    Publication
    Restricted
    Screening of three commercial plant peroxidases for the removal of phenolic compounds in membrane bioreactors
    (Taylor and Francis Group, Taylor and Francis, 2012-01-04) Máximo, María Fuensanta; Gómez Gómez, María; Murcia Almagro, María Dolores; Ortega Requena, Salvadora; Barbosa, D.S.; Vayá, G.; Ingeniería Química; Facultad de Química
    A comparative study of three plant peroxidases, horseradish (HRP), soybean (SBP) and artichoke (AKPC), was carried out to select the most appropriate one for 4-chlorophenol treatment in an ultrafiltration membrane reactor. Soybean peroxidase showed the highest enzymatic activity, followed by HRP and AKPC. The same tendency was observed in a discontinuous tank reactor, where SBP attained more than 90% of 4-chlorophenol removal within the pH range tested. The optimum temperature was 30 °C, with SBP showing highest thermostability. With the ultrafiltration membrane reactor, SBP attained the highest operational stability, with 4-chlorophenol conversions of around 90% in the permeate stream for up to 200 minutes. Finally, permeate samples were analysed and no significant amount of enzyme was detected, so the observed loss of activity, less pronounced with SBP, was attributed to enzyme adsorption on the polymeric products deposited on the membrane surface. Soybean peroxidase was selected as the most appropriate peroxidase for future research.