A Novel Electro-Fenton Process with H₂O₂ Generation in a Rotating Disk Reactor for Organic Pollutant Degradation

Abstract

The feasibility of the electrogeneration of H2O2 and degradation of an organic pollutant by a novel electro-Fenton (EF) process was demonstrated using dual rotating graphite felt disks to supply oxygen instead of the traditional aeration method, with methyl orange (MO) as the model pollutant. The effects of rotating speed, current density, and pH on the generation of hydrogen peroxide (H2O2) were investigated. At a current density of 50 A/m2, a rotating speed of 10 rpm, and a pH of 3, the concentration of H2O2 reached 116 mg/L in 1 h, which was much higher than that at 0 rpm (37 mg/L). The complete removal of 25 mg/L MO was achieved within 15 min, while the total organic carbon removal efficiency reached 58.7% at 2 h, which was almost 3-fold higher than that at 0 rpm (14.9%). The rotation of disk cathodes resulted in the efficient production of H2O2 without oxygen aeration, offering a potentially cost-effective EF method for degrading organic pollutants.

Highly efficient electrosynthesis of hydrogen peroxide on a superhydrophobic three-phase interface by natural air diffusion

“…It is noteworthy that the energy consumption was 118.0 kWh kg −1 excluding the energy consumption of aeration. It has been well known that a higher O 2 supply promotes the production of H 2 O 2 24 , but the oxygen utilization efficiency (OUE) of GDEs is extremely low (usually <1%) 25,26 . Yu et al proposed an improved GDE to synthesize H 2 O 2 , which increased the OUE to 8.84%, and the yield of H 2 O 2 reached 11.16 mg h −1 cm −2 at the current density of 35.7 mA cm −2 .…”

Activated Carbon as a Cathode for Water Disinfection through the Electro-Fenton Process

“…The GAC cathode produced a significant amount of H 2 O 2 in the rage of 3-20 mg/L after 60 min (Table 1). This is particularly important, because other functional, higher priced carbonaceous materials typically produce 12-36 mg/L H 2 O 2 in similar settings [30][31][32].…”

A Hybrid Approach: Indirect Electro‐Oxidation Followed by In Situ Electrogeneration of H2O2 in Real Textile Effluent

“…At potentials more negative than -1.0 V, the hydrogen peroxide concentration decreased and reached zero due to the formation of water molecules (O 2 reduction with four electrons), Eq. (13).…”

“…Its generation efficiency depends upon the oxygen reduction potential on the cathode material employed [9]. Redox-modified as well as non-catalytic carbon electrodes such as graphite, reticulated vitreous carbon, activated carbon fibers, polyacrylonitrile-based carbon fibers, and carbon felt cathodes, besides the boron doped diamond and mercury electrodes, have been investigated for in situ generation of H 2 O 2 , by employing rotating disk reactors, divided or undivided electrochemical cells [10][11][12][13][14]. Wang et al has reported about the in situ generation of H 2 O 2 and electro-Fenton process of real textile effluents by employing graphite [15], activated carbon [16], and a graphite packed bed cathode [17].…”