• Gas diffusion electrode (GDE) is a suitable setup for practical water treatment. • Electrochemical H2O2 production is an economically competitive technology. • High current efficiency of H2O2 production was obtained with GDE at 5–400 mA/cm2. • GDE maintained high stability for H2O2 production for ~1000 h. • Electro-generation of H2O2 enhances ibuprofen removal in an E-peroxone process.
![]()
This study evaluated the feasibility of electrochemical hydrogen peroxide (H
2O
2) production with gas diffusion electrode (GDE) for decentralized water treatment. Carbon black-polytetrafluoroethylene GDEs were prepared and tested in a continuous flow electrochemical cell for H
2O
2 production from oxygen reduction. Results showed that because of the effective oxygen transfer in GDEs, the electrode maintained high apparent current efficiencies (ACEs,>80%) for H
2O
2 production over a wide current density range of 5–400 mA/cm
2, and H
2O
2 production rates as high as ~202 mg/h/cm
2 could be obtained. Long-term stability test showed that the GDE maintained high ACEs (>85%) and low energy consumption (<10 kWh/kg H
2O
2) for H
2O
2 production for 42 d (~1000 h). However, the ACEs then decreased to ~70% in the following 4 days because water flooding of GDE pores considerably impeded oxygen transport at the late stage of the trial. Based on an electrode lifetime of 46 days, the overall cost for H
2O
2 production was estimated to be ~0.88 $/kg H
2O
2, including an electricity cost of 0.61 $/kg and an electrode capital cost of 0.27 $/kg. With a 9 cm
2 GDE and 40 mA/cm
2 current density, ~2–4 mg/L of H
2O
2 could be produced on site for the electro-peroxone treatment of a 1.2 m
3/d groundwater flow, which considerably enhanced ibuprofen abatement compared with ozonation alone (~43%–59% vs. 7%). These findings suggest that electrochemical H
2O
2 production with GDEs holds great promise for the development of compact treatment technologies for decentralized water treatment at a household and community level.
相似文献