Carbon nanotube filter functionalized with iron oxychloride for flow-through electro-Fenton

Electro-Fenton is a promising advanced oxidation process for the treatment of emerging contaminants from water bodies. Here, we developed a robust and affordable flow-through electro-Fenton process to degrade antibiotic tetracycline. The key component of this technology is an electroactive and porous carbon nanotube filter functionalized with FeOCl. These nanoscale FeOCl significantly promoted the generation of HO center dot by facilitating efficient cycling of Fe3+/Fe2+. Electrochemical filtration of 0.04 mM tetracycline at -0.8 V vs. Ag/AgCl and a flow rate of 1.5 mL min(-1) resulted in an oxidative flux of 5.32 +/- 0.41 mmol h(-1) m(-2). Relative to conventional batch reactor, the proposed system showed enhanced tetracycline degradation kinetics because of the convection-enhanced mass transport. The underlying working mechanism of the system was proposed based on various advanced assessments and density functional theory calculations. This study should offer new insights about the rational design of continuous-flow systems towards efficient removal of various contaminants.