Grantee Research Project Results
Final Report: Power Field Monitoring Equipment from Wetland Detritus Materials using Microbial Fuel Cell
EPA Grant Number: SU834703Title: Power Field Monitoring Equipment from Wetland Detritus Materials using Microbial Fuel Cell
Investigators: Chow, Alex , O’Rourke, Elizabeth , Dai, Jianing , Conner, William , Wilson, William
Institution: Clemson University
EPA Project Officer: Page, Angela
Phase: I
Project Period: August 15, 2010 through August 14, 2011
Project Amount: $9,994
RFA: P3 Awards: A National Student Design Competition for Sustainability Focusing on People, Prosperity and the Planet (2010) RFA Text | Recipients Lists
Research Category: Pollution Prevention/Sustainable Development , P3 Challenge Area - Air Quality , P3 Awards , Sustainable and Healthy Communities
Objective:
Detritus or organic matter stored in forest/wetland/estuarine ecosystems represents a large potential source of energy. Microbial fuel cells (MFC), which can convert organic wastes into electricity, are a potential tool to harvest this renewable energy to power field equipment in remote areas. Field monitoring equipment in remote areas requires portable batteries (chemical fuel cells) to operate. Conventional batteries are composed of many heavy metals such as lead, cadmium, and chromium, which can pollute the environment. MFC provides an alternative green energy that can reduce the use of conventional fuel cells.
This ultimate goal of the study is to harvest microbial energy from detritus layers in wetlands to support field research work. The specific objectives of the Phase I is listed as follows:
Obj. 1: Determine temporal and spatial variations in electricity generation of in situ MFC
Obj. 2: Evaluate DOM composition and hydrological factors on energy production of MFC
Obj. 3: Identify optimal conditions that can maximize electricity generation for MFC
The student team conducted both field and controlled laboratory experiments to achieve the study objectives. Two sets of in situ MFCs were constructed in a freshwater forested wetland at Winyah Bay, South Carolina to determine the temporal and spatial variations of electricity production by in situ MFC. Power data collection has been collected since October 2010 and will be continued until August 2011. Analysis takes into account the combination of environmental factors such as the local air temperature and the water level data (Obj. 1).
The student team used both dual-chamber and column reactors representing batch and continuous flow mode to examine DOM composition and hydrological factors on MFC performance, respectively. The experiments involved measurement aiming to elucidate the effects of depths of anode, water levels, electrode size, configuration of anodes, and sources of litter materials (Obj. 2). Combining results from both the field and laboratory studies, the student team suggested optimal conditions and setup that can maximize MFC electricity generation and the strategies in the Phase II study (Obj. 3)
Summary/Accomplishments (Outputs/Outcomes):
Obj. 1 - Temperature appears a major factor affecting in situ MFC performance. Results indicated the power output of the in situ MFC model installed in the forested wetland at Winyah Bay followed the local air temperature changes. Temperature can affect the microbial activity in soil. A continuous power output was observed if the air temperature reaches 15-20°C, and the in situ MFC generated power up to 2.2mW/m2 and 0.85mW/2 at average.
Obj. 2 – Depth of anode in the sediment layer could affect the internal resistance of the MFC. The lowest MFC internal resistance of 7.5 kΩ was achieved when the anode was placed 1 cm below the surface. A similar value (8 kΩ) was observed when the anode is at a 5 cm depth. However, the internal resistance increased to 10.9 kΩ at 10 cm. In addition, the water level also affected the internal resistance of the MFC. The internal resistance increased with an increase of the distance between the anode and cathode. In addition, greater sizes of electrodes could exponentially increase the power output density. An anode with 1.1 m2 generated 21 times more power than that of an anode with 0.22 m2.
Three types of litter materials, cypress (Taxodium distichum), tupelo (Nyssa aquatica) and pine (Pinus palustris), were used as the organic substrates in this study. Greater carbon contents were found from cypress and tupelo litters. Whole cypress and tupelo litters could produce up to 0.7 and 0.65 mW/m2 in our column reactor and litter extracts could produce 2.4 mW/m2 and 0.85 mW/m2 in the batch mode, respectively. Electricity generation of pine was roughly 4 to 10 times less than those values.
Conclusions:
Based on the results of Phase I, important factors that affect MFC performance are listed as follows (Obj. 3):
- Proposed configuration of in-situ MFC in wetland: anodes should be set 1 to 5 cm below the sediment surface and cathodes should float directly above the anode.
- Larger surface area of electrodes, especially the anodes, can increase the power output.
- Different types of electrodes need to be used to construct the in situ MFC. Carbon fiber brush is suitable as a cathode in aqueous phases, whereas solid electrodes such as a graphite rod is good in soil and sediment as an anode.
- Seasonal temperature has significant influence on the power output.
- Litters from forested wetland include cypress (Taxodium distichum) and tupelo (Nyssa aquatica) could have greater carbon content and can generate greater electricity via MFC from pine (Pinus palustris).
Journal Articles on this Report : 1 Displayed | Download in RIS Format
Other project views: | All 1 publications | 1 publications in selected types | All 1 journal articles |
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Type | Citation | ||
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Dai J, Wang J, Chow A, Conner W. Electrical energy production from forest detritus in a forested wetland using microbial fuel cells. GCP-BIOENERTY 2014;7(2):244-252. |
SU834703 (Final) |
Exit |
Supplemental Keywords:
Alternative energy source, renewable fuel, waste to energyRelevant Websites:
Hobcaw Barony: http://www.hobcawbarony.org/
South Atlantic Chapter, Society of Wetland Scientists: http://www.sws.org/
The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.