Effect of Fenton process as a pretreatment in the phytoremediation of metronidazole by Scirpus lacustris

Abstract

ABSTRACT The present study evaluated the effect of the Fenton process as pretreatment for metronidazole (MNZ) removal coupled with a phytoremediation system using Scirpus lacustris as macrophyte. Initial concentrations of 0.5, 5, 10, 15, and 20 mg MNZ/L were studied in batch cultures. Results obtained in the MNZ removal by phytoremediation showed efficiencies of 93 ± 2%, 81 ± 4%, 85 ± 1%, 84 ± 2%, and 87 ± 6%, respectively. The metronidazole pretreated by the Fenton process and subsequently fed to the phytoremediation system increased the removal efficiencies up to 93 ± 3%, 99 ± 1%, 99 ± 4%, 94 ± 2%, and 94 ± 3%, respectively. Individual studies with Scirpus lacustris in touch with metronidazole displayed relative growth rates of 0.02–0.04 d−1, showing the not toxic effect of the antibiotic on the macrophyte growth. On the other hand, the BMG kinetic model best describes the removal of MNZ by phytoremediation. Finally, applying the Fenton process as a pretreatment makes the MNZ more assimilable for the phytoremediation system, converting the integration of Fenton with the phytoremediation like other attractive technology to be considered in removing emerging compounds.