title: Electrochemical wastewater treatment: influence of the type of carbon and of nitrogen on the organic load removal.
abstract: Boron-doped diamond (BDD) and Ti/Pt/PbO2anodes were utilized to perform the electrodegradation of synthetic samples containing humic acid in the presence of different organic and inorganic carbon-containing and nitrogen-containing compounds. The influence of the chloride ion in the degradation process of the different synthetic samples was also assessed. The results showed that the anodic oxidation process can efficiently degrade recalcitrant compounds such as humic acid. The presence of carbonate in solution enhances the nitrogen removal, whereas it hinders the oxidation of the organic compounds. When organic nitrogen is present, it is converted to NH4+, which in turn is oxidized to nitrate and to volatile nitrogen compounds. Hydroxyl radicals are more prone to oxidize the organic nitrogen than the ammonium nitrogen. The presence of chloride enhances the organic matter and nitrogen removal rates, BDD being the anode material that yields the highest removals.
authors.affiliation: FibEnTech/MTP Unit and Department of Chemistry, University of Beira Interior, 6201-001, Covilhã, Portugal. annabelf@ubi.pt.
authors.forename: Annabel
authors.initials: A
authors.lastname: Fernandes
authors.affiliation: FibEnTech/MTP Unit and Department of Chemistry, University of Beira Interior, 6201-001, Covilhã, Portugal.
authors.forename: João
authors.initials: J
authors.lastname: Coelho
authors.affiliation: FibEnTech/MTP Unit and Department of Chemistry, University of Beira Interior, 6201-001, Covilhã, Portugal.
authors.forename: Lurdes
authors.initials: L
authors.lastname: Ciríaco
authors.affiliation: FibEnTech/MTP Unit and Department of Chemistry, University of Beira Interior, 6201-001, Covilhã, Portugal.
authors.forename: Maria José
authors.initials: MJ
authors.lastname: Pacheco
authors.affiliation: FibEnTech/MTP Unit and Department of Chemistry, University of Beira Interior, 6201-001, Covilhã, Portugal.
authors.forename: Ana
authors.initials: A
authors.lastname: Lopes
mesh_terms: D001895:Boron / Q000737:chemistry; D002244:Carbon / Q000737:chemistry*; D018130:Diamond / Q000737:chemistry; D055664:Electrochemical Techniques / Q000379:methods*; D004566:Electrodes; D006812:Humic Substances / Q000032:analysis*; D007854:Lead / Q000737:chemistry; D009566:Nitrates; D009584:Nitrogen / Q000737:chemistry*; D009930:Organic Chemicals; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry; D017671:Platinum Compounds / Q000737:chemistry; D014025:Titanium / Q000737:chemistry; D014865:Waste Disposal, Fluid / Q000379:methods*; D062065:Wastewater / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry
chemical_list: D001895:Boron; D002244:Carbon; D018130:Diamond; D006812:Humic Substances; D007854:Lead; D009566:Nitrates; D009584:Nitrogen; D009930:Organic Chemicals; D010087:Oxides; D017671:Platinum Compounds; D014025:Titanium; D062065:Wastewater; D014874:Water Pollutants, Chemical; C047365:lead oxide
keywords: BDD anode; Chloride influence; Electrochemical treatment; Humic acid; Nitrogen removal; Persistent organic pollutants; Ti/Pt/PbO2 anode