Search

To effectively solve the problem of tetracycline (TC) and Cu2+ contamination in wastewater, this study innovatively proposed a low-energy flow-electrode capacitive deionization (FCDI) technology to simultaneously remove TC and Cu2+ from wastewater. The removal efficiencies of TC and Cu2+ using FCDI was investigated under various voltages, electrode flow rates, influent flow rates, and electrode liquid concentrations. The results showed that the removal efficiency of TC and Cu2+ was 60.78% and 84.43%, respectively. The energy consumption for TC and Cu2+ removal was only 1.76 and 1.10 kWh kg−1, which was lower than other electrochemical systems. The ion removal performance of the FCDI system remained stable after six cycles of continuous operation. These findings demonstrated the promising potential of FCDI as an innovative technology for the simultaneous removal of TC and Cu2+, presenting a significant prospects for application in the water treatment field. [ABSTRACT FROM AUTHOR]

Herein, a carbon felt (CF) cathode modified by the acidic oxidised carbon nanotubes (OCNTs) exhibited a high yield of the H2O2 generation in electro-Fenton. Rotating disk electrode (RDE) measurements showed that the selective generation of H2O2 occurred on the CF cathode coated by OCNTs (OCNTs/CF), which was attributed to the high amount of oxygen-containing functional groups in OCNTs. Moreover, the pollutant degradation efficiency could almost reach 100% within 60 min in electro-Fenton with OCNTs/CF as the cathode. Furthermore, the pollutant removal efficiency was kept constant after five consecutive cycles, indicating the high stability of OCNTs/CF cathode. Besides, the hydrophilicity of OCNTs/CF cathode was significantly enhanced owing to the abundant oxygen-contained functional groups on the surface of the OCNTs/CF cathode, which facilitated the mass transfer between the OCNTs/CF cathode and the reactants in the bulk solution. To reveal the possible mechanism in electro-Fenton equipped with the OCNTs/CF cathode, quenching experiments and electron paramagnetic resonance (EPR) investigations were further conducted. This work provided valuable insights into the fabrication of the non-metallic cathode with a high ability towards H2O2 generation in electro-Fenton for efficient pollutant removal. [ABSTRACT FROM AUTHOR]

BACKGROUND The extracellular electron transfer (EET) between microbes and electrodes modified by graphene‐based functional material has attracted increasing attention. EET is an important process through which the anode can act as the acceptor for the electrons produced via microbial respiration, and it also plays a key role in organic matter degradation and nutrient cycling in the environment. RESULTS: Our results showed that the interaction between microbes and carbon felt (CF) electrodes decorated with bio‐reduced graphene oxide (GO‐br) was significantly enhanced compared to that between the unmodified CF electrode and microbes. The promoted biological current production and cyclic voltammetric (CV) current response indicated the considerable electro‐activity of the GO‐br‐CF electrode. diffusion resistance (Rdif) of the GO‐br‐CF electrode decreased significantly by 97.3% from 2.76 × 105 ± 7644 Ω at the initial incubation stage to 7341 ± 1322 Ω after 58 h of incubation time for GO‐br decoration. We also noticed that the GO‐br‐CF electrode intermittently poised at +0.1 V (vs Ag/AgCl/KCl sat.) was favorable for EET. The GO‐br‐CF electrode, which enhanced MFC performance significantly, was further used as the anode in a microbial fuel cell (MFC). CONCLUSION: Overall, the results of this study indicated the decoration of CF electrode with GO‐br could regulate the electrochemical activity of the electrode and the EET process between the microbes and electrode. The elevated electrochemical activity and EET were attributed to the rapid decrease in the diffusion resistance (Rdif) of the GO‐br‐CF electrode. [ABSTRACT FROM AUTHOR]