Electrolysis assisted persulfate with annular iron sheet as anode for the enhanced degradation of 2, 4-dinitrophenol in aqueous solution.

Annular iron sheet (AIS), playing a dual role of anode electrode and source of activator, was combined with electrolysis technology for the activation of persulfate to improve the degradation of 2, 4-dinitrophenol (DNP) in aqueous solution. In this study, effects of current density (0–10.0 mA/cm 2 ), persulfate (PS) dosage (0–8.0 mM), initial pH (3.0–11.0), reaction temperature (25–60 °C) and reaction time (0–30 min) on COD removal of DNP in aqueous solution were investigated, respectively. COD removal reached its maximal value (63.4%) after 15 min treatment due to the synergistic effect in electro/AIS/PS system under the optimal conditions. Furthermore, comparative studies of 7 different experimental processes were setup. In addition, the reasonable DNP degradation pathway was proposed based on intermediates detected by HPLC. According to characterization analysis of SEM-EDS, XRD and XPS of the generated flocculation in electro/AIS/PS system, the possible reaction mechanism was proposed in detail. In a word, the electrolysis process coupled with annular iron sheet as anode activating persulfate technology shows a significant synergetic effect in enhancing degradation of DNP in aqueous solution. [ABSTRACT FROM AUTHOR]