Synergic degradation Chloramphenicol in photo-electrocatalytic microbial fuel cell over Ni/MXene photocathode

Abstract

The abuse of Chloramphenicol (CAP) has become the increasingly serious environmental problem for its harmfulness and toxicity. A novel strategy was achieved by photocatalysis coupled with microbial fuel cell (Photo-MFC) over Ni/MXene photocathode for enhancing the degradation efficiency of (CAP). It was demonstrated that the best degradation efficiency of CAP can reach 82.62% (original concentration of 30 mg/L) after 36 h under the optimal conditions (pH = 2). Based on density functional theory (DFT) calculations and high-performance liquid chromatography-mass (HPLC-MS) spectrometry, it was speculated that the degradation mechanism of CAP in Photo-MFC over Ni/MXene photoelectrode was achieved by destroying the two asymmetric centers and nitro, including the hydrodechlorination, nitro reduction reaction, hydroxylation reaction, cleavage of CN bond and ring-opening reaction of benzene ring. Finally, the ecotoxicity evaluation of the degradation products showed that the CAP degradation in the Ni/MXene modified photo-MFC system showed a remarkable tendency to the low-toxicity level.