A Fenton-like system combined by Co2+ and potassium Monopersulfate for the treatment of benzoic acid

In this paper, the Fenton-like oxidation system combined by Co²⁺ and potassium Monopersulfate (PMS) for the treatment of benzoic acid (BA) was investigated. The BA degradation was increased with the increasing of Co²⁺ dosage and PMS dosage. However, when the molar ratios of Co²⁺ to PMS were higher than 1:50, the increase of BA degradation rates were not so visible. The new system was more efficient than the conventional Fenton system for it shown obvious catalytic activity in a much wider pH range from 4 to 10. The Co²⁺/PMS system led the formation of sulfate radicals, which were identified with quenching studies using specific alcohols. The sulfate radicals are stronger oxidants than hydroxyl radicals especially in neutral pH range. The Co²⁺/PMS Fenton-like oxidation process could be considered as one of the most promising technologies for practical application for water treatment.