title: Microbial fuel cell assisted nitrate nitrogen removal using cow manure and soil.
abstract: Microbial fuel cells (MFCs) are emerging wastewater treatment systems with a proven potential for denitrification. In this study, we have developed a high-rate denitrifying MFC. The anode consisted of cow manure and fruit waste and the cathode consisted of cow manure and soil. The initial chemical oxygen demand (COD)/nitrate nitrogen (NO3 (-)-N) was varied from 2 to 40 at the cathode while keeping the anode ratio fixed at 100. NO3 (-)-N removal rate of 7.1 ± 0.9 kg NO3 (-)-N/m(3) net cathodic compartment (NCC)/day was achieved at cathode COD/NO3 (-)-N ratio 7.31 with the current density of 190 ± 9.1 mA/m(2) and power density of 31.92 ± 4 mW/m(2) of electrode surface area. We achieved an open-circuit voltage (OCV) of 410 ± 20 mV at initial cathodic NO3 (-)-N of 0.345 g/l. The cathode COD/NO3 (-)-N ratio had a significant influence on MFC's OCV and nitrate removal rate. Lower OCV (<150 mV) and NO3 (-)-N removal rates were observed at COD/NO3 (-)-N ratio >12 and <7. Experiments done at different cathode pH values indicated that the optimum pH for denitrification was 7. Under optimized biochemical conditions, nitrate removal rate of 6.5 kg NO3 (-)-N/m(3) net cathodic compartment (NCC)/day and power density of 210 mW/m(2) were achieved in a low resistance MFC. The present study thus demonstrates the utility of MFCs for the treatment of high nitrate wastes.
authors.affiliation: Department of Biology, Indian Institute of Technology-Jodhpur, Rajasthan, 342011, India.
authors.forename: Ankisha
authors.initials: A
authors.lastname: Vijay
authors.affiliation: Department of Biology, Indian Institute of Technology-Jodhpur, Rajasthan, 342011, India.
authors.forename: Monika
authors.initials: M
authors.lastname: Vaishnava
authors.affiliation: Department of Biology, Indian Institute of Technology-Jodhpur, Rajasthan, 342011, India. meenuchhabra@iitj.ac.in.
authors.forename: Meenu
authors.initials: M
authors.lastname: Chhabra
mesh_terms: D000818:Animals; D001674:Bioelectric Energy Sources; D057919:Biological Oxygen Demand Analysis; D002417:Cattle; D058440:Denitrification; D004566:Electrodes; D008372:Manure; D009566:Nitrates / Q000737:chemistry; D009584:Nitrogen / Q000302:isolation & purification*; D009589:Nitrogen Oxides; D012987:Soil; D018505:Waste Management / Q000379:methods*; D062065:Wastewater
chemical_list: D008372:Manure; D009566:Nitrates; D009584:Nitrogen; D009589:Nitrogen Oxides; D012987:Soil; D062065:Wastewater
keywords: Biocathode; Cow manure; Heterotrophic denitrification; Microbial fuel cell; Soil; Wastewater treatment