Promoting the performance of electrooxidation-PMS system for degradation of tetracycline by introduction of MnFe2O4/CNT as a third-electrode

Abstract

In this work, MnFe2O4/CNT was introduced into electrochemical oxidation (EC)-peroxymonosulfate (PMS) system to be served as a third electrode. In which, 20 wt% MnFe2O4/CNT due to its excellent physical characterization was proven to promote the catalytic degradation performance of tetracycline (TC). The optimal conditions for EC-20 wt% MnFe2O4/CNT-PMS on TC removal efficiency was investigated by dosage of catalyst, dosage of oxidant, current density and initial pH of TC. When 20 wt% MnFe2O4/CNT was injected at 0.1 g·L−1, PMS was injected at 6 m M, current density was 10 mA·cm−2, initial pH was 5.9, and reaction time was 120 min, TC removal rate reached 87.7%. The effect of humic acid (HA) on TC degradation was investigated by simulating real water bodies. The results showed that EC-20 wt% MnFe2O4/CNT-PMS system was less affected by water background. Judging by capturing free radicals’ experiments, it proved that this novel system facilitates to make much more •OH and SO4−• as active species in degradation of TC. The degradation mechanism of TC in the EC-20 wt% MnFe2O4/CNT-PMS system was estimated by XPS analysis of catalysts before and after the reaction. This research provides a new perspective for electrochemical oxidation by introducing nanomaterials as microelectrodes.