title: Electrochemical treatment of concentrate from reverse osmosis of sanitary landfill leachate.
abstract: Conventional sanitary landfill leachate treatment has recently been complemented and, in some cases, completely replaced by reverse osmosis technology. Despite the good quality of treated water, the efficiency of the process is low and a large volume of reverse osmosis concentrate has to be either discharged or further treated. In this study, the use of anodic oxidation combined with electro-Fenton processes to treat the concentrate obtained in the reverse osmosis of sanitary landfill leachate was evaluated. The anodic oxidation pretreatment was performed in a pilot plant using an electrochemical cell with boron-doped diamond electrodes. In the electro-Fenton experiments, a boron-doped diamond anode and carbon-felt cathode were used, and the influence of the initial pH and iron concentration were studied. For the experimental conditions, the electro-Fenton assays performed at an initial pH of 3 had higher organic load removal levels, whereas the best nitrogen removal was attained when the electrochemical process was performed at the natural pH of 8.8. The increase in the iron concentration had an adverse impact on treatment under natural pH conditions, but it enhanced the nitrogen removal in the electro-Fenton assays performed at an initial pH of 3. The combined anodic oxidation and electro-Fenton process is useful for treating the reverse osmosis concentrate because it is effective at removing the organic load and nitrogen-containing species. Additionally, this process potentiates the increase in the biodegradability index of the treated effluent.
authors.affiliation: FibEnTech/UBI and Department of Chemistry, Universidade da Beira Interior, 6201-001 Covilhã, Portugal; Dép. de Chimie, Faculté des Sciences de Gabès, Université de Gabès, Cité Erriadh, 6072 Gabès, Tunisia.
authors.forename: Lazhar
authors.initials: L
authors.lastname: Labiadh
authors.affiliation: FibEnTech/UBI and Department of Chemistry, Universidade da Beira Interior, 6201-001 Covilhã, Portugal. Electronic address: annabelf@ubi.pt.
authors.forename: Annabel
authors.initials: A
authors.lastname: Fernandes
authors.affiliation: FibEnTech/UBI and Department of Chemistry, Universidade da Beira Interior, 6201-001 Covilhã, Portugal.
authors.forename: Lurdes
authors.initials: L
authors.lastname: Ciríaco
authors.affiliation: FibEnTech/UBI and Department of Chemistry, Universidade da Beira Interior, 6201-001 Covilhã, Portugal.
authors.forename: Maria José
authors.initials: MJ
authors.lastname: Pacheco
authors.affiliation: Dép. de Chimie, Faculté des Sciences de Gabès, Université de Gabès, Cité Erriadh, 6072 Gabès, Tunisia.
authors.forename: Abdellatif
authors.initials: A
authors.lastname: Gadri
authors.affiliation: Dép. de Chimie, Faculté des Sciences de Gabès, Université de Gabès, Cité Erriadh, 6072 Gabès, Tunisia; Dép. de Chimie, Faculté des Sciences de Bizerte, Université de Carthage, 7021 Jarzouna, Tunisia; Laboratoire Photovoltaïque, Centre de Recherches et des Technologies de l'Energie Technopole Borj Cedria, Bp 95, Hammamm Lif, 2050, Tunisia.
authors.forename: Salah
authors.initials: S
authors.lastname: Ammar
authors.affiliation: FibEnTech/UBI and Department of Chemistry, Universidade da Beira Interior, 6201-001 Covilhã, Portugal.
authors.forename: Ana
authors.initials: A
authors.lastname: Lopes
mesh_terms: D001673:Biodegradation, Environmental; D057919:Biological Oxygen Demand Analysis; D001895:Boron; D002244:Carbon; D018130:Diamond; D055664:Electrochemical Techniques / Q000295:instrumentation / Q000379:methods*; D004566:Electrodes; D006861:Hydrogen Peroxide; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000737:chemistry; D009584:Nitrogen / Q000737:chemistry / Q000302:isolation & purification; D009995:Osmosis; D010084:Oxidation-Reduction; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D018508:Water Purification / Q000379:methods*
chemical_list: D014874:Water Pollutants, Chemical; D002244:Carbon; D018130:Diamond; D006861:Hydrogen Peroxide; D007501:Iron; D009584:Nitrogen; D001895:Boron
keywords: Anodic oxidation; Electro-Fenton; Reverse osmosis concentrate; Sanitary landfill leachate