Nitrogen is one of major contaminants in wastewater; however, nitrogen, as bio-elements for crop growth, is the indispensable fertilizer in agriculture. In this study, two-chamber microbial fuel cells （MFCs） were fi...Nitrogen is one of major contaminants in wastewater; however, nitrogen, as bio-elements for crop growth, is the indispensable fertilizer in agriculture. In this study, two-chamber microbial fuel cells （MFCs） were first operated with microorganisms in anode chamber and potassium ferricyanide as catholyte. After being success- fully startup, the two-chamber MFCs were re-constructed to three-chamber MFCs which were used to recover the NO-3 -N and NH＋4 -N of synthetic wastewater into value- added nitrogenous fertilizer from cathode chamber and anode chamber, respectively. Ferric nitrate was used as the sole electron acceptor in cathode, which also was used to evaluate the NO-3 -N recover efficiency in the case major anion of NO3 in cathode. The output voltage of these MFCs was about 600-700 mVat an external load of 500 Ω. About 47% NH＋4 -N in anode chamber and 83% NO-3 -N in cathode chamber could be recovered. Higher current density can selectively improve the recovery efficiency of both NH＋4-N and NO3 -N. The study demonstrated a nitrogen recovery process from synthetic wastewater using three-chamber MFCs.展开更多
Microbial fuel cells (MFCs) are bioelectrochemical systems that convert chemical energy contained in organic matter into electrical energy by using the catalytic (metabolic) activity of living microorganisms. Mediator...Microbial fuel cells (MFCs) are bioelectrochemical systems that convert chemical energy contained in organic matter into electrical energy by using the catalytic (metabolic) activity of living microorganisms. Mediator-less two chamber H-type MFCs were constructed in the current study, using dairy digester microbial population as anode inocula to convert finely ground pine tree (Avicel) at 2% (w/v) to electricity. MFCs were placed at 37°C and after the circuit voltage was stabilized on d9, bovine rumen microorganisms cultured anaerobically for 48 hrs in cellulose broth media were added to treatment group of MFC at 1% v/v dosage. MFC power and current across an external resistor were measured daily for 10 d. At the end of incubation on d19 head space gas and anode chamber liquid solutions were collected and analyzed for total gas volume and composition, and volatile fatty acids, respectively. Addition of enriched rumen microorganisms to anaerobic anode chamber increased cellulose digestibility and increased both CO2 and methane production;however, it decreased the methane to CO2 ratio. Over the experimental period, electricity generation was increased with rumen microorganism addition, and power density normalized to anode surface area was 17.6 to 67.2 mW/m2 with average of 36.0 mW/m2 in treatment, while control group had 3.6 to 21.6 (AVE 12.0) mW/m2. These observations imply that biocatalysis in MFCs requires additional cellulolytic activities to utilize structural biomass in bioenergy production.展开更多
基金This study was supported by the Natural Science Foundation of Fujian （No. 2012J05105）, the National Natural Science Foundation of China （Grant No. 51208490）, the Knowledge Innovation Program of the Chinese Academy of Sciences （No. IUEQN201306） and the Hundred Talents Program of the Chinese Academy of Sciences.
文摘Nitrogen is one of major contaminants in wastewater; however, nitrogen, as bio-elements for crop growth, is the indispensable fertilizer in agriculture. In this study, two-chamber microbial fuel cells （MFCs） were first operated with microorganisms in anode chamber and potassium ferricyanide as catholyte. After being success- fully startup, the two-chamber MFCs were re-constructed to three-chamber MFCs which were used to recover the NO-3 -N and NH＋4 -N of synthetic wastewater into value- added nitrogenous fertilizer from cathode chamber and anode chamber, respectively. Ferric nitrate was used as the sole electron acceptor in cathode, which also was used to evaluate the NO-3 -N recover efficiency in the case major anion of NO3 in cathode. The output voltage of these MFCs was about 600-700 mVat an external load of 500 Ω. About 47% NH＋4 -N in anode chamber and 83% NO-3 -N in cathode chamber could be recovered. Higher current density can selectively improve the recovery efficiency of both NH＋4-N and NO3 -N. The study demonstrated a nitrogen recovery process from synthetic wastewater using three-chamber MFCs.
文摘Microbial fuel cells (MFCs) are bioelectrochemical systems that convert chemical energy contained in organic matter into electrical energy by using the catalytic (metabolic) activity of living microorganisms. Mediator-less two chamber H-type MFCs were constructed in the current study, using dairy digester microbial population as anode inocula to convert finely ground pine tree (Avicel) at 2% (w/v) to electricity. MFCs were placed at 37°C and after the circuit voltage was stabilized on d9, bovine rumen microorganisms cultured anaerobically for 48 hrs in cellulose broth media were added to treatment group of MFC at 1% v/v dosage. MFC power and current across an external resistor were measured daily for 10 d. At the end of incubation on d19 head space gas and anode chamber liquid solutions were collected and analyzed for total gas volume and composition, and volatile fatty acids, respectively. Addition of enriched rumen microorganisms to anaerobic anode chamber increased cellulose digestibility and increased both CO2 and methane production;however, it decreased the methane to CO2 ratio. Over the experimental period, electricity generation was increased with rumen microorganism addition, and power density normalized to anode surface area was 17.6 to 67.2 mW/m2 with average of 36.0 mW/m2 in treatment, while control group had 3.6 to 21.6 (AVE 12.0) mW/m2. These observations imply that biocatalysis in MFCs requires additional cellulolytic activities to utilize structural biomass in bioenergy production.
