title: Coupling biofiltration process and electrocoagulation using magnesium-based anode for the treatment of landfill leachate.
abstract: In this research paper, a combination of biofiltration (BF) and electrocoagulation (EC) processes was used for the treatment of sanitary landfill leachate. Landfill leachate is often characterized by the presence of refractory organic compounds (BOD/COD < 0.13). BF process was used as secondary treatment to remove effectively ammonia nitrogen (N-NH4 removal of 94%), BOD (94% removed), turbidity (95% removed) and phosphorus (more than 98% removed). Subsequently, EC process using magnesium-based anode was used as tertiary treatment. The best performances of COD and color removal from landfill leachate were obtained by applying a current density of 10 mA/cm(2) through 30 min of treatment. The COD removal reached 53%, whereas 85% of color removal was recorded. It has been proved that the alkalinity had a negative effect on COD removal during EC treatment. COD removal efficiencies of 52%, 41% and 27% were recorded in the presence of 1.0, 2.0 and 3.0 g/L of sodium bicarbonate (NaHCO3), respectively. Hydroxide ions produced at the cathode electrode reacted with the bicarbonate ions to form carbonates. The presence of bicarbonates in solution hampered the increase in pH, so that the precipitation of magnesium hydroxides could not take place to effectively remove organic pollutants.
authors.affiliation: Institut national de la recherche scientifique (INRS-Eau Terre et Environnement), Université du Quebec, 490 rue de la Couronne, Quebec, QC, G1K 9A9, Canada. Electronic address: oumar.dia@ete.inrs.ca.
authors.forename: Dia
authors.initials: D
authors.lastname: Oumar
authors.affiliation: Institut national de la recherche scientifique (INRS-Eau Terre et Environnement), Université du Quebec, 490 rue de la Couronne, Quebec, QC, G1K 9A9, Canada. Electronic address: patrick.drogui@ete.inrs.ca.
authors.forename: Drogui
authors.initials: D
authors.lastname: Patrick
authors.affiliation: Centre de Recherche Industrielle du Québec (CRIQ), 333 rue Franquet, Québec, QC, G1P 4C7, Canada. Electronic address: Gerardo.Buelna@criq.qc.ca.
authors.forename: Buelna
authors.initials: B
authors.lastname: Gerardo
authors.affiliation: Centre de Recherche Industrielle du Québec (CRIQ), 333 rue Franquet, Québec, QC, G1P 4C7, Canada. Electronic address: Rino.Dube@criq.qc.ca.
authors.forename: Dubé
authors.initials: D
authors.lastname: Rino
authors.affiliation: E2Metrix Inc, 3905 Rue Lesage, Sherbrooke, QC, J1L 2Z9, Canada. Electronic address: ibensalah@e2metrix.com.
authors.forename: Ben Salah
authors.initials: BS
authors.lastname: Ihsen
mesh_terms: D000641:Ammonia / Q000737:chemistry; D057919:Biological Oxygen Demand Analysis; D004564:Electrocoagulation / Q000295:instrumentation / Q000379:methods*; D004566:Electrodes; D005374:Filtration / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D008274:Magnesium; D009584:Nitrogen / Q000737:chemistry / Q000378:metabolism; D009930:Organic Chemicals / Q000737:chemistry; D010758:Phosphorus / Q000737:chemistry / Q000378:metabolism; D017693:Sodium Bicarbonate / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D018508:Water Purification / Q000295:instrumentation / Q000379:methods
chemical_list: D009930:Organic Chemicals; D014874:Water Pollutants, Chemical; D010758:Phosphorus; D000641:Ammonia; D017693:Sodium Bicarbonate; D008274:Magnesium; D009584:Nitrogen
keywords: Ammonia nitrogen; Biofiltration; Electrocoagulation; Landfill leachate; Magnesium electrode; Refractory COD