Electrocoagulation of bio-filtrated landfill leachate: Fractionation of organic matter and influence of anode materials.
Electrocoagulation (EC) was employed to treat residual organic matter from a landfill leachate pretreated by an aerated bio-filter system. Organic matter (humic acids (HA), fulvic acids (FA) and hydrophilic compounds (Hyl)) was fractionated using DAX-8 resin in order to estimate the efficiency of EC on each fraction. Initial characterization of the bio-filtrated landfill leachate showed that humic substances (HA + FA) represented nearly 90% of TOC. The effects of current densities, type of anode (Aluminum versus iron), and treatment time on the performance of COD removal were investigated. The best COD removal performances were recorded at a current density ranging between 8.0 and 10 mA cm-2during 20 min of treatment time. Under these conditions, 70% and 65% of COD were removed using aluminum and iron electrodes, respectively. The fractionating of organic matter after EC treatment revealed that HA was completely removed using either aluminum or iron anode. However, FA and Hyl fractions were partially removed, with the percentages varying from 57 to 60% and 37-46%, respectively. FA and Hyl removal were quite similar using either aluminum or iron anode. Likewise, a significant decrease in 254-nm absorbance was recorded (UV254removal of 79-80%) using either type of anode. These results proved that EC is a suitable and efficient approach for treating the residual refractory organic matter from a landfill leachate previously treated by a biological system.
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.
Oumar
O
Dia
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.
Patrick
P
Drogui
Centre de Recherche Industrielle du Québec (CRIQ), 333 rue Franquet, Québec, QC, G1P 4C7, Canada. Electronic address: Gerardo.Buelna@criq.qc.ca.
Gerardo
G
Buelna
Centre de Recherche Industrielle du Québec (CRIQ), 333 rue Franquet, Québec, QC, G1P 4C7, Canada. Electronic address: Rino.Dube@criq.qc.ca.
Rino
R
Dubé
E2Metrix Inc, 3905 Rue Lesage, Sherbrooke, QC, J1L 2Z9, Canada. Electronic address: ibensalah@e2metrix.com.
Ben Salah
BS
Ihsen
D000535:Aluminum / Q000737:chemistry; D001578:Benzopyrans / Q000032:analysis* / Q000737:chemistry; D005591:Chemical Fractionation; D004564:Electrocoagulation / Q000379:methods*; D004566:Electrodes; D005374:Filtration; D006812:Humic Substances / Q000032:analysis*; D007501:Iron / Q000737:chemistry; D012037:Refuse Disposal / Q000379:methods; D064091:Waste Disposal Facilities; D014874:Water Pollutants, Chemical / Q000032:analysis*
D001578:Benzopyrans; D006812:Humic Substances; D014874:Water Pollutants, Chemical; D000535:Aluminum; D007501:Iron; C005023:fulvic acid
Bio-filtration; Electrocoagulation; Fulvic acids; Humic acids; Landfill leachate