A tubular ceramic membrane coated with TiO2-P25 for radial addition of H2O2 towards AMX removal from synthetic solutions and secondary urban wastewater

Autor: Reynel Martínez Castellanos, Vítor J.P. Vilar, Miguel Angel Mueses, Jennyfer Diaz-Angulo, Alexandre Diório, Rosângela Bergamasco, Marcelo Fernandes Vieira, Ana Gomes, Márcia Dezotti, Fiderman Machuca-Martínez
Rok vydání: 2021
Předmět:
Zdroj: Environmental Science and Pollution Research. 29:42120-42129
ISSN: 1614-7499
0944-1344
DOI: 10.1007/s11356-021-14297-4
Popis: This work aims to integrate several hydrogen peroxide (H2O2) activation mechanisms, photolysis (UVC irradiation), chemical electron transfer (TiO2-P25 photocatalysis), and reaction with TiO2-P25 in dark conditions, for reactive oxygen species (ROS) generation towards the removal of contaminants of emerging concern (CECs), in a single unit operated in continuous-flow mode. An H2O2 stock solution is fed by the lumen side of a tubular ceramic membrane, delivering the oxidant to the (i) catalyst immobilized in the membrane shell-side and (ii) annular reaction zone (ARZ, space between membrane shell-side and outer quartz tube) where CECs contaminated water flows with a helix trajectory, being activated by UV light provided by four lamps placed symmetrically around the reactor. First, the effect of several parameters in the removal of a CEC target molecule, amoxicillin (AMX), was evaluated using a synthetic solution ([AMX]inlet = 2.0 mg L-1): (i) light source (UVA or UVC radiation), (ii) H2O2 dose, (iii) H2O2 injection method (radial permeation vs. upstream injection), and (iv) number of TiO2-P25 layers deposited on the membrane. The UVC/H2O2/TiO2 system with radial addition of H2O2 (20 mg L-1) and 9-TiO2-P25 layers provided the highest AMX removal efficiency (72.2 ± 0.5%) with a UV fluence of 45 mJ cm-2 (residence time of 4.6 s), due to the synergic effect of four mechanisms: (i) AMX photolysis, (ii) H2O2 photocleavage, (iii) TiO2-P25 photoactivation, and (iv) chemical reactions between H2O2 and TiO2-P25. The urban wastewater matrix showed a negative effect on AMX removal (~44%) due to the presence of ROS scavengers and light-filtering species.
Databáze: OpenAIRE
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