Degradation of norfloxacin in a heterogeneous electro-Fenton like system coupled with sodium chloride as the electrolyte

Abstract

To utilize the chloridion in practical pharmaceutical wastewater and to minimize the negative impact of chloridion on the aerobic bacteria in the biochemical pool, a composite electrocatalyst consisting of CeO2 and CoFe2O4 loaded on electrospun carbon nanofibers (CeO2/CoFe2O4@C-NCNFs-800) was prepared and employed for NOR degradation in the heterogeneous electro-Fenton/Cl- (hetero-EF/Cl-) system. A superior NOR degradation efficiency was discovered in the hetero-EF/Cl- system than in the hetero-EF system, which benefited from the generation of more selective oxidants (ClO·) when hydroxylradical (·OH) and Cl- were present simultaneously. The 20 min operation allowed 99.54% NOR removal under the appropriate conditions (pH = 6.05, current = 40 mA, and [Cl-] = 0.1 M) with a reaction rate constant (kobs) of 0.3032 min-1. According to the quenching and the probe experiments, ·OH, ClO·, and singletoxygen (1O2) were confirmed to be predominance during NOR degradation, whose steady-state concentrations were 2.00 × 10-11 M, 1.39 × 10-11 M, and 1.19 × 10-11 M, respectively. In short, this study offered a probable method to utilize chloridion in practical pharmaceutical wastewater.