title: In situ reactive oxygen species production for tertiary wastewater treatment.
abstract: The goal of this research was to develop a new approach for tertiary water treatment, particularly disinfection and removal of refractory organic compounds, without adding any chemical. Hydrogen peroxide can indeed be produced from dissolved oxygen owing to electrochemical processes. Using various current intensities (1.0 to 4.0 A), it was possible to in situ produce relatively high concentration of H2O2 with a specific production rate of 0.05 × 10(-5) M/min/A. Likewise, by using ultraviolet-visible absorption spectroscopy method, it was shown that other reactive oxygen species (ROS) including HO(*) radical and O3 could be simultaneously formed during electrolysis. The ROS concentration passed from 0.45 × 10(-5) M after 20 min of electrolysis to a concentration of 2.87 × 10(-5) M after 100 min of electrolysis. The disinfection and the organic matter removal were relatively high during the tertiary treatment of municipal and domestic wastewaters. More than 90 % of organic compounds (chemical oxygen demand) can be removed, whereas 99 % of faecal coliform abatement can be reached. Likewise, the process was also effective in removing turbidity (more than 90 % of turbidity was removed) so that the effluent became more and more transparent.
authors.affiliation: Institut National de la Recherche Scientifique (INRS-Eau Terre et Environnement), Université du Quebec, 490 rue de la Couronne, Quebec, QC, Canada, G1K 9A9, lea.guitaya@ete.inrs.ca.
authors.forename: Léa
authors.initials: L
authors.lastname: Guitaya
authors.forename: Patrick
authors.initials: P
authors.lastname: Drogui
authors.forename: Jean François
authors.initials: JF
authors.lastname: Blais
mesh_terms: D057919:Biological Oxygen Demand Analysis; D004203:Disinfection / Q000379:methods*; D004572:Electrolysis; D006861:Hydrogen Peroxide / Q000138:chemical synthesis*; D009930:Organic Chemicals / Q000737:chemistry*; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry; D017382:Reactive Oxygen Species / Q000138:chemical synthesis; D014865:Waste Disposal, Fluid / Q000379:methods; D062065:Wastewater; D018508:Water Purification / Q000379:methods*
chemical_list: D006861:Hydrogen Peroxide; D009930:Organic Chemicals; D010100:Oxygen; D017382:Reactive Oxygen Species; D062065:Wastewater