On-line electrochemical production of ferrate (VI) for odor control

Sulfur-containing compounds are one kind of representative odorant from sewage, wastewater treatment plants and associated with various industries. In this study, the on-line electrogenerated ferrate (VI) technique was used to remove gaseous methyl mercaptan (CH3SH) for odor control. The second-order reaction kinetics of CH3SH oxidation with ferrate was identified and meanwhile, the stability of ferrate in high alkaline medium was investigated for the first time. The influencing factors including alkalinity, current density and co-existing ions on the ferrate formation were also investigated with details in this study. Experimental results show that for the ferrate formation, the 14 mol dm−3 NaOH is the optimal alkalinity at 4.5 mA cm−2; increasing current density and decreasing the SO42− concentration are helpful for the ferrate production. This fundamental research provides essential understanding for developing the on-line electrochemical ferrate process for gaseous sulfur-containing compound degradation in odor control.

► On-line electrogenerated Fe(VI) technique was used to remove CH3SH for odor control. ► The second-order reaction kinetics of CH3SH oxidation with ferrate was identified. ► The stability of ferrate in high alkaline medium was studied for the first time. ► The influencing factors on the ferrate formation were investigated with details.