Fermentation pre-treatment of landfill leachate for enhanced electron recovery in a microbial electrolysis cell.
Pre-fermentation of poorly biodegradable landfill leachate (BOD5/COD ratio of 0.32) was evaluated for enhanced current density (j), Coulombic efficiency (CE), Coulombic recovery (CR), and removal of organics (BOD5 and COD) in a microbial electrolysis cell (MEC). During fermentation, the complex organic matter in the leachate was transformed to simple volatile fatty acids, particularly succinate and acetate in batch tests, but mostly acetate in semi-continuous fermentation. Carbohydrate had the highest degree of fermentation, followed by protein and lipids. j, CE, CR, and BOD5 removal were much greater for an MEC fed with fermented leachate (23 A/m(3) or 16 mA/m(2), 68%, 17.3%, and 83%, respectively) compared to raw leachate (2.5 A/m(3) or 1.7 mA/m(2), 56%, 2.1%, and 5.6%, respectively). All differences support the value of pre-fermentation before an MEC for stabilization of BOD5 and enhanced electron recovery as current when treating a recalcitrant wastewater like landfill leachate.
Swette Center for Environmental Biotechnology, The Biodesign Institute at Arizona State University, P.O. Box 875701, Tempe, AZ 85287-5701, USA. Electronic address: mmali4@asu.edu.
Mohamed
M
Mahmoud
Prathap
P
Parameswaran
César I
CI
Torres
Bruce E
BE
Rittmann
D000693:Anaerobiosis; D061249:Batch Cell Culture Techniques; D001674:Bioelectric Energy Sources; D057919:Biological Oxygen Demand Analysis; D004572:Electrolysis / Q000379:methods*; D004583:Electrons; D005232:Fatty Acids, Volatile / Q000032:analysis; D005285:Fermentation; D013997:Time Factors; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*
D005232:Fatty Acids, Volatile; D014874:Water Pollutants, Chemical
Anode respiring bacteria; Coulombic efficiency; Current density; Microbial electrolysis cell; Pre-fermentation