Progress 10/01/09 to 09/30/14

Outputs
Target Audience: Energy researchers, graduate and undergraduate students, K-12 students and K-12 science teachers; government agency personnel in environmental, natural resources, and energy departments; consulting engineers Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? The course called "Biomass conversion to bioenergy" which was developed last year was offered for the second time during spring semester 2014. The official course description was: an exploration of the science and technologies used for energy production from bio-based materials, including agricultural biomass and solid waste sources. Four graduate students and fifteen undergraduates successfully completed the course. Professional development: The PI, one graduate student and one undergraduate student who are part of the MFC research team participated by presenting and learning at the annual international meeting of the American Society of Agricultural and Biological Engineers (ASABE) in Montreal, Quebec, Canada, July 13-16, 2014. In addition, the PI, three graduate students, and one of the undergraduate researchers attended the 2014 Electrochem Ohio conference which was held September 19-20 in Columbus, Ohio. One of the graduate students presented a poster at the conference. How have the results been disseminated to communities of interest? Results have been disseminated in refereed journal articles and scholarly presentations. The PI, one graduate student and one undergraduate student who are part of the MFC research team participated by presenting their research at the annual international meeting of the American Society of Agricultural and Biological Engineers (ASABE) in Montreal, Quebec, Canada, July 13-16, 2014. REsults were also presented via a poster in the 2014 Electrochem Ohio conference which was held September 19-20 in Columbus, Ohio. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Under the first goal (1.) Expand scientific knowledge of microbial fuel cells (MFCs) as a bioenergy option: the bacteria that use anaerobic respiration metabolic pathways to generate electricity in MFCs were found to consistently out compete the growth of methanogenic microorganisms thus suppressing methane formation in MFCs. The microbial consortia within a ruminant's gastrointestinal tract was found to be exoelectrogeneic and cellulolytic, thus enabling MFCs to use less refined substrates for power generation. Various biological entities in the cathode compartment were explored including photosynthetic marine algae and human and bovine blood products (hemoglobin, red blood cells, and whole blood). Preliminary results showed minor improvements in performance but more work is needed. The use of MFC technology for other purposes beyond electricity generation was explored, specifically Microbial Desalination Cells (MDCs) were constructed and experimented upon. Desalination was 100% effective in 24 hours or less, but electricity generation was relatively low. Life Cycle Analyses are being performed to assess the sustainability of MFCs and MDCs. (2.) Increase power production in MFCs: Data collected during previous years on use of nanostructured cathodic coatings are being further analyzed. Preliminary results showed that graphite powder coating produced the greatest increase in peak power density among the treatments to graphite bar base current collectors, and that no replicable power enhancements were observed among the stainless steel mesh coatings. Carbon nanotube coatings did not improve MFC performance with either base material. Voltage self-amplification circuits and applied electric fields were also explored as ways to increase peak-to-peak voltage outputs, accelerate cation diffusion, increase cellulose catabolic rates, and accomplish faster electron transport from the anode to cathode in the MFC. Results showed that voltage self-amplification successfully boosted the voltage of four MFCs in parallel while also reducing the activation losses of these cells.

Publications

• Type: Conference Papers and Presentations Status: Published Year Published: 2014 Citation: Faze, Natasha R., Gauri M. Girme, Trent A. Bower, Ann D. Christy, and Bhavik R. Bakshi. 2014. Life Cycle Analysis of a microbial desalination cell. American Society of Agricultural and Biological Engineers Annual International Meeting. ASABE Paper No.14-1913148. Montreal, Quebec, Canada: July 13-16, 2014. 7 p.
• Type: Conference Papers and Presentations Status: Published Year Published: 2014 Citation: Girme, Gauri M., Natasha R. Faze, Trent A. Bower, and Ann D. Christy. 2014. Algae powered microbial desalination cells. American Society of Agricultural and Biological Engineers Annual International Meeting. ASABE Paper No.14-1913232. Montreal, Quebec, Canada: July 13-16, 2014. 14 p.
• Type: Conference Papers and Presentations Status: Published Year Published: 2014 Citation: Walter, Reed R., Trent A. Bower, and Ann D. Christy. 2014. Enhancing the renewable power output of microbial fuel cells by applying an electric field. American Society of Agricultural and Biological Engineers Annual International Meeting. ASABE Paper No.14-1912916. Montreal, Quebec, Canada: July 13-16, 2014. 5 p.
• Type: Conference Papers and Presentations Status: Published Year Published: 2014 Citation: Wang, Ying-Chin, Trent A. Bower, Ann D. Christy. 2014. Effect of catholytes on performance of blood-based microbial fuel cells. American Society of Agricultural and Biological Engineers Annual International Meeting. ASABE Paper No.14-1913042. Montreal, Quebec, Canada: July 13-16, 2014. 9 p.
• Type: Conference Papers and Presentations Status: Published Year Published: 2014 Citation: Christy, Ann D. 2014. Students' selection of topics for a professional development course. 2014 ASEE Annual Conference, American Society for Engineering Education. Paper # AC 2014-10643. Indianapolis, Indiana: June 16-18, 2014. 5 p.
• Type: Theses/Dissertations Status: Published Year Published: 2014 Citation: Girme, Gauri M. 2014. Algae powered microbial desalination cells. MS Thesis. The Ohio State University.
• Type: Theses/Dissertations Status: Published Year Published: 2014 Citation: Wang, Ying-Chin. 2014. Using red blood cells in microbial fuel cell catholyte solution to improve electricity generation. MS Thesis. The Ohio State University.

Progress 01/01/13 to 09/30/13

Outputs
Target Audience: Energy researchers, graduate and undergraduate students, K-12 students and K-12 science teachers; government agency personnel in environmental, natural resources, and energy departments; consulting engineers Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Training activities: A course called "Biomass conversion to bioenergy" was developed and offered for the first time during spring semester 2013. The official course description was: an exploration of the science and technologies used for energy production from bio-based materials, including agricultural biomass and solid waste sources. Twelve graduate students and one undergraduate successfully completed the course. Professional development: The PI, two graduate students and two undergraduate students who are part of the MFC research team participated by presenting and learning at the annual international meeting of the American Society of Agricultural and Biological Engineers (ASABE) in Kansas City, Missouri, July 21-24, 2013. In addition, the PI and one of the undergraduate researchers attended the 2013 Fuel Cell Seminar and Energy Exposition which was held October 21-24 in Columbus, Ohio. How have the results been disseminated to communities of interest? Results have been disseminated in refereed journal articles and scholarly presentations. The PI, two graduate students and two undergraduate students who are part of the MFC research team participated by presenting posters of their reserach at the annual international meeting of the American Society of Agricultural and Biological Engineers (ASABE) in Kansas City, Missouri, July 21-24, 2013. What do you plan to do during the next reporting period to accomplish the goals? Research will continue on voltage self-amplification and electric fields in MFCs, and on blood-based MFCs for biomedical applications. New projects applying MFC technology to desalination and using algae to increase oxygen levels in the cathode compartment are underway. Also, a life cycle analysis will be performed to begin to quantify the sustainability of MFC technology.

Impacts
What was accomplished under these goals? Under the first goal (1.) Expand scientific knowledge of microbial fuel cells (MFCs) as a bioenergy option, the bacteria that use anaerobic respiration metabolic pathways to generate electricity in MFCs were found to consistently out compete the growth of methanogenic microorganisms thus suppressing methane formation in MFCs. In addition, preliminary work was begun on blood-based MFCs for biomedical applications by using red blood cells to enhance oxygen levels in the cathode compartment of the fuel cell. Under the second goal (2.) Increase power production in MFCs, voltage self-amplification circuits and applied electric fields were explored as ways to increase peak-to-peak voltage outputs, accelerate cation diffusion, increase cellulose catabolic rates, and accomplish faster electron transport from the anode to cathode in the MFC. Results showed that voltage self-amplification successfully boosted the voltage of four MFCs in parallel while also reducing the activation losses of these cells. Specifically, the self oscillating voltage booster circuit increased the RMS voltage by nearly 50 percent and the circuit's peak-to-peak voltage output effectively emulated a signal boosted more than 425 percent above the original MFC output voltage.

Publications

• Type: Journal Articles Status: Published Year Published: 2013 Citation: Rismani-Yazdi, H., S.M. Carver, A.D. Christy, Z. Yu, K. Bibby, J. Peccia, and O.H. Tuovinen. 2013. Suppression of methanogenesis in cellulose-fed microbial fuel cells in relation to performance, metabolite, and microbial population. Bioresource Technology 129(1): 281-288
• Type: Conference Papers and Presentations Status: Published Year Published: 2013 Citation: Christy, Ann D. 2013. "Student portfolios for assessing ABET a-k outcomes." Proceedings of the 2013 ASEE North Central Section Conference. Columbus, Ohio, April 6, 2013. 12 p.
• Type: Conference Papers and Presentations Status: Published Year Published: 2013 Citation: Miller, A.J., J. Adair, A. Culbertson, T.A. Bower, A.D. Christy, and G. Kaletunc. 2013. A new air-cathode design for use with microbial fuel cells. ASABE Annual Meeting Poster No.13-1620679. Kansas City, Missouri, July 23, 2013.
• Type: Conference Papers and Presentations Status: Published Year Published: 2013 Citation: Walter, R., T.A. Bower, and A.D. Christy. 2013. Electrical field amplified microbial fuel cells. ASABE Annual Meeting Poster No.13-1619292. Kansas City, Missouri, July 23, 2013.
• Type: Conference Papers and Presentations Status: Published Year Published: 2013 Citation: Wang, Ying-Chin, A. Stratton, and A.D. Christy. 2013. Feasibility of blood-based microbial fuel cells for biomedical applications. ASABE Annual Meeting Poster No.13-1619598. Kansas City, Missouri, July 23, 2013.
• Type: Theses/Dissertations Status: Published Year Published: 2013 Citation: Bower, Trent A. 2013. "Voltage Self-Amplification and Signal Conditioning for Enhanced Microbial Fuel Cell Performance." Electronic Thesis. Ohio State University. https://etd.ohiolink.edu/

Progress 01/01/12 to 12/31/12

Outputs
OUTPUTS: Innovative electrical circuit designs were also explored for linking multiple MFCs together in an array to increase power output. Studied: (1) the effects of increasing the surface area on MFC cathodes on energy production, (2) compared graphite plate and stainless steel mesh as base current collectors and (3) explored alternative circuit designs to increase power generation by conditioning electrical output from MFCs and linking multiple MFCs together. To increase the cathodic surface area, three types of micro or nano-structure materials were investigated, carbon nanotubes, activated carbon, and graphite powder. Carbon nanotube powder and graphite powder were attached to two types of base current collectors: plain graphite bar stock coated with silver epoxy and stainless steel mesh covered in conductive paint. The graphite powder and carbon nanotube cathodes were created by coating the outside of a graphite bar electrode with silver epoxy and then packing graphite powder or carbon nanotube powder onto the outside of the electrode. The stainless steel cathodes were created by coating the outside of the stainless steel mesh with conductive paint and then packing graphite powder, carbon nanotube powder, or activated carbon onto the surface of the electrode. Two circuits for MFCs were investigated to try to increase power output and linkability as the low electric potential produced by MFCs (typically less than one volt) has limited the broad application of this technology. Circuits studied were a low power transformer and a low voltage integrated circuit recently released by Advanced Linear Devices. Both have the potential to operate at very low voltages and isolate the current drawn from the electricity-generating bacteria, allowing microbial fuel cells to become more versatile power sources and thus able to power a much wider range of practical applications. Study is in progress. Presentations made at American Society of Agricultural and Biological Engineers (ASABE) Annual Meeting, Dallas ,TX, July 29-Aug 1, 2012; Ohio Association of Agricultural Educators Conference and Agricultural Education Hands-on-Training Conference, Columbus, Ohio, June 13, 2012 (invited Workshop on Microbial Fuel Cells). 3 articles written. PARTICIPANTS: Olli Tuovinen, Professor, Dept. of Microbiology, Ohio State University (MFC microbiology); Lingying Zhao, Associate Professor, Dept. of Food, Agricultural & Biological Engineering, Ohio State University (MFC applications). Graduate students: Trent Bower, Brandon Gifford, Gauri Girme, and Ying-Chin Wang. TARGET AUDIENCES: Researchers, graduate and undergraduate students, K-12 students and K-12 science teachers PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Results on cathode coatings showed that graphite powder produced the greatest increase in peak power density among the coating treatments to graphite bar base current collectors, and that no replicable power enhancements were observed among the stainless steel mesh coatings. The electrical circuit research has enabled conversion of the DC signal from the microbial fuel cells into an AC signal that creates a 3-fold gain in amplification of the voltage. This voltage will not only power some electrical devices natively, but it also enables the charging of nickel-metal hydride batteries commonly used in consumer electronics.

Publications

• Chen, Q., A.D. Christy, M.E. Owens, D. Bortz, W. Greene, and B. King. 2012. Two-plus-two construction management programs and articulation agreements. International Journal of Construction Education and Research. 8(1): 4-25.
• Weatherington-Rice, J., E.K. Kim, A.D. Christy, Y.W. Kang. 2012. Predicting nutrient and contaminant transport via fractures in glacially-related fine-grained soils using field and laboratory soil texture data. Soil Science Society of America Annual Meeting. Division: S11 Soils & Environmental Quality, Abstract 169-6 and poster number 2409.
• Yost, A.E., A.D. Christy, L. Zhao, and O.H. Tuovinen. 2012. Impact of Increased Surface Area Cathodes Using Nanostructures in Microbial Fuel Cells for Electricity Production. ASABE Annual Meeting Paper No.12-1337011. St. Joseph, Mich: ASABE. 13p

Progress 01/01/11 to 12/31/11

Outputs
OUTPUTS: Microbial fuel cells (MFCs) are bio-electrochemical devices which microbiologically convert the chemical energy of an organic substrate into electricity. When using cellulose as the substrate, the process links cellulose hydrolysis with fermentative acidogenesis and anaerobic respiration using the electrode as the electron acceptor. External load or resistance between the anode and cathode electrode of an MFC affects the flow of electrons produced as does also the surface area of those electrodes. ACTIVITIES: The first objective of this phase of the study was to test how changing resistances affects bacterial diversity and the production of current, power, and metabolic intermediates in MFCs innoculated with dairy rumen microorganisms. Duplicate microbial fuel cells (MFCs) were operated under four different resistances: 20, 249, 480, and 1000 ohms. The eight total MFCs were initially inoculated with a consortium of dairy rumen microorganisms and provided with cellulose as substrate. After ten weeks, based on the DGGE analysis of 16SrRNA genes, clear differences were observed between bacterial populations for the four resistances. Maximum current (0.43 mA) and maximum power density (66 mW/m2) were produced by the 20-ohm MFCs. Conversely, minimum current (0.26 mA) was produced by the 1000-ohm MFCs. Those MFCs with 249, 480, and 1000-ohm external resistances produced 57.5, 27, and 47 mW/m2 respectively. The 1000-ohm MFCs produced 75% more short chain fatty acids than the 20-ohm MFCs (7760 mg/L versus 4423 mg/L). The second objective of this phase of the study was to test how changing surface area of the cathode electrode affects power production in MFCs inoculated with dairy rumen microorganisms. Three types of micro or nano-structure materials were investigated for enhancing the surface area of MFC cathodes. These materials were carbon nanotubes, activated carbon, and graphite powder. Two different current collectors and methods of attachment were used to create the cathodes which were run in triplicate: graphite bars covered with silver epoxy which had graphite powder or carbon nanotube powder embedded in the epoxy and stainless steel mesh coated with conductive graphite paint which had carbon nanotube powder, activated carbon granules, or graphite powder embedded into the paint. The stainless steel mesh electrodes were found to produce 107% higher power density than the graphite bar electrodes. Preliminary results indicated that the carbon nanotubes did not enhance energy production and instead greatly increased the internal resistance of the MFC. The graphite powder cathodes made with silver epoxy on graphite bar produced a maximum power density 47% higher than the reference graphite bar cathode, and the activated carbon cathodes made with conductive paint on stainless steel mesh produced a maximum power density 52 % higher than the highest reference stainless steel mesh cathode. EVENTS: Ohio Association of Agricultural Educators Conference and Agricultural Education Hands-on-Training Conference, Columbus, Ohio, June 14-16, 2011 (invited Workshop on Microbial Fuel Cells). PARTICIPANTS: Collaborators: [1.] Olli Tuovinen, Professor, Dept. of Microbiology, Ohio State University (MFC microbiology); [2.] Lingying Zhao, Associate Professor, Dept. of Food, Agricultural & Biological Engineering, Ohio State University (MFC applications and project management). Graduate students: [1.] Sarah Carver, [2.] Trent Bower, [3.] Alan Yost, [4.] Brandon Gifford TARGET AUDIENCES: Researchers, graduate and undergraduate students, K-12 students and K-12 science teachers PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Energy demand is increasing across the globe while conventional energy sources such as oil and coal are becoming more scarce and more costly. Renewable and sustainable technologies become attractive alternatives as we consider our long-term energy security as a nation. Bio-energy sources such as biodiesel and bio-ethanol may be part of the solution, but in both cases there are inefficiencies to be overcome in the process of chemically or biologically converting biomass (e.g., corn, soybeans, switchgrass, etc.) into a liquid or gaseous fuel and then burning that fuel in a combustion engine to get useful work from the biomass. This research project explored a new technology, the microbial fuel cell, that converts biomass directly into useful energy in the form of bio-electricity without needing an intermediate combustion step. The challenge is to discover how to increase the electrical output of these devices. Factors that affect the power production capability of MFCs are the spacing between anode and cathode electrodes, microorganisms, feedstock, proton exchange membrane material, internal and external resistance, and the surface areas of the electrodes. The last two factors were experimentally studied in our laboratory on microbial fuel cells using dairy rumen microorganisms and cellulose substrate. Our research showed higher circuit loads produced less electricity (as measured by current and power density), significantly different microbial populations, and increased buildup of intermediate fatty acid metabolites. This suggests that by manipulating the external resistance, the balance between fermentative acidogenesis and anaerobic respiration can be controlled in MFCs and power output increased. Results of studies on three types of micro or nano-structure materials were, carbon nanotubes, activated carbon, and graphite powder, suggest that the activated carbon on stainless steel and graphite powder on graphite outperformed the other treatments.

Publications

• Rismani-Yazdi, H., A.D. Christy, S.M. Carver, Z. Yu, B.A. Dehority, and O.H. Tuovinen. 2011. Effect of external resistance on bacterial diversity and metabolism in microbial fuel cells. Bioresource Technology 102(1): 278-283.
• Christy, A.D. and H. Rismani-Yazdi. 2011. (Abstract) Effects of Changing External Resistance in Microbial Fuel Cells. Ohio Journal of Science 111(1): A-7.
• Kim, E.K., Y.W. Kang, A.D. Christy, and J. Weatherington-Rice. 2011. Ternary diagram modeling of soil texture data for predicting subsurface fracturing in glacially related fine-grained materials. Trans. ASABE 54(4): 1325-1331.
• Kim, E.K., Y.W. Kang, A.D. Christy, and J. Weatherington-Rice. 2011. Predicting preferential flow of pollutants via fractures using field and laboratory soil texture data. ASABE Paper No.11-11335. St. Joseph, Mich: ASABE. 11p.
• Kim, E.K., A.D. Christy, Y.W. Kang, and J. Weatherington-Rice. 2011. (Abstract)Evaluation of a fracture prediction model using laboratory experiments & field soil texture data. Ohio Journal of Science 111(1): A-9. (Peer reviewed abstract).
• Christy, A.D. 2011. Engaging Students to Prepare them for the Engineering Profession and Reflect upon their Undergraduate Career. ASABE Paper No.11-11605. St. Joseph, Mich: ASABE. 8p.

Progress 01/01/10 to 12/31/10

Outputs
OUTPUTS: Microbial fuel cells (MFCs) are bio-electrochemical devices which microbiologically convert the chemical energy of a substrate into electricity. When using cellulose as the substrate, the process links cellulose hydrolysis with fermentative acidogenesis and anaerobic respiration using the electrode as the electron acceptor. External load or resistance between the anode and cathode electrode of an MFC affects the flow of electrons produced. ACTIVITIES: The objective of this phase of the study was to test how changing resistances affects bacterial diversity and the production of current, power, and metabolic intermediates in MFCs innoculated with dairy rumen microorganisms. Duplicate Microbial fuel cells (MFCs) were operated under four different resistances: 20, 249, 480, and 1000 ohms. The eight total MFCs were initially inoculated with a consortium of dairy rumen microorganisms and provided with cellulose as substrate. After ten weeks, based on the DGGE analysis of 16SrRNA genes, clear differences were observed between bacterial populations for the four resistances. Maximum current (0.43 mA) and maximum power density (66 mW/m2) were produced by the 20-ohm MFCs. Conversely, minimum current (0.26 mA) was produced by the 1000-ohm MFCs. Those MFCs with 249, 480, and 1000-ohm external resistances produced 57.5, 27, and 47 mW/m2 respectively. The 1000-ohm MFCs produced 75% more short chain fatty acids than the 20-ohm MFCs (7760 mg/L versus 4423 mg/L). We are continuing to test new electrode and membrane designs including use of micro- and nano-composite materials on the electrode surfaces. EVENTS: (1.) Ohio Water Quality and Waste Management Conference: Waste to Energy for Rural Ohio, Columbus, Ohio, February 4, 2010: invited presentation "Using wastes to produce electricity with Microbial Fuel Cells." (2.) Scarlet and Grey Ag Day, May 2010: presentation and hands-on activities for 300 middle school students. (3.) Sino-US Symposium on New Technology of Biogas and Low Concentration Waste Water Treatment, Jinan, China, October 17-19, 2010: invited presentation "Using wastes to produce electricity with Microbial Fuel Cells."(4.) As part of an OSU Gateway Grant entitled "Establishing China-US Collaborations in Agricultural Environments and Renewable Energy," I presented MFC research findings at invited seminars during October 8-20, 2010 at seven Chinese universities: Tongji University (Shanghai), Fudan University (Shanghai), Shanghai Jiaotong University, Zhejiang University (Hangzhou), China Agricultural University (Beijing), Tsinghua University (Beijing), and Shandong University (Jinan). (5.) Columbus Public School Professional Development Day, Columbus, Ohio December 8, 2010: invited presentation "Teaching biology, chemistry, physics, and bioenergy with Microbial Fuel Cells" PARTICIPANTS: Collaborators: [1.] Olli Tuovinen, Professor, Dept. of Microbiology, Ohio State University (MFC microbiology); [2.] Lingying Zhao, Associate Professor, Dept. of Food, Agricultural & Biological Engineering, Ohio State University (MFC applications and project management); and [3.] Zhontang Yu, Assistant Professor, Dept. of Animal Sciences, Ohio State University (MFC microbiology). Graduate students: [1.] Carol Ann Mullin, [2.] Sarah Carver, [3.] Trent Bower, [4.] Alan Yost, [5.] Brandon Gifford TARGET AUDIENCES: Researchers, graduate and undergraduate students, K-12 students and teachers PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Energy demand is increasing across the globe while conventional energy sources such as oil and coal are becoming more scarce and more costly. Renewable and sustainable technologies become attractive alternatives as we consider our long-term energy security as a nation. Bio-energy sources such as biodiesel and bio-ethanol may be part of the solution, but in both cases there are inefficiencies to be overcome in the process of chemically or biologically converting biomass (e.g., corn, soybeans, switchgrass, etc.) into a liquid or gaseous fuel and then burning that fuel in a combustion engine to get useful work from the biomass. This research project explored a new technology, the microbial fuel cell, that converts biomass directly into useful energy in the form of bio-electricity without needing an intermediate combustion step. The challenge is to discover how to increase the electrical output of these devices. Studies on microbial fuel cells using dairy rumen microorganism and cellulose substrate showed higher circuit loads produced less electricity (as measured by current and power density), significantly different microbial populations, and increased buildup of intermediate fatty acid metabolites. This suggests that by manipulating the external resistance, the balance between fermentative acidogenesis and anaerobic respiration can be controlled in MFCs and power output increased.

Publications

• Zwierschke, Kerry Hughes and Christy, Ann D. 2010. Anaerobic Bioreactor Landfills. In Encyclopedia of Agricultural, Food, and Biological Engineering, 2nd edition (Dennis R. Heldman, editor), London, UK: Taylor and Francis. pp. 42-45. (Peer reviewed).
• Kim, E.K., Y.W. Kang, A.D. Christy, and J. Weatherington-Rice. 2010. Laboratory method for predicting boundary conditions of soil textures that support fracture development. Applied Engineering in Agriculture 26(6): 973-982.

Progress 01/01/09 to 12/31/09

Outputs
OUTPUTS: ACTIVITIES: A unique anaerobic microbial consortia was tested in MFCs at moderately thermophilic temperatures (50-60 degrees C) to identify the optimal temperature for the combined process of cellulose digestion and electricity generation. This required modifying the engineering design and selecting materials specifically for the elevated temperature regime to reduce the rate of evaporation. We were able to minimize the evaporation and test new electrode and membrane designs. Research on nano-composite materials to enhance bacteria adhesion and improve the reaction kinetics at the anode electrode is still in the preliminary stages. We have been identifying and meeting with potential collaborators who have access to nano and micro manufacturing equipment, allowing us to develop miniature anode electrodes with nano structured surfaces using electrospun composite polymers with conductive properties. EVENTS: (1.) Ohio State University (OSU) Engineering freshman scholars Green Engineering program Jan 22, 2009: presentation and lab for 70 freshmen students. (2.) Cuyahoga County Youth Advisory Council April 16, 2009: presentation and lab demonstration for 30 inner city high school students. (3.) Scarlet and Grey Ag Day May 15, 2009: presentation and hands-on activities for 300 middle school students. (4.) Engineers in Motion Summer Camp July 6, 2009: presentation for 40 high school students. (5.) Women in Engineering Summer Camp July 20, 2009: presentation and lab for 55 incoming freshmen women. (6.) OSU/ OARDC Renewable Energy Workshop Nov. 12, 2009: invited presentation "Microbial Fuel Cells: Cellulose Conversion to Electricity" to 140 registered attendees. PARTICIPANTS: Collaborators : (1.) Olli Tuovinen, Professor, Dept. of Microbiology, Ohio State University (MFC microbiology); (2.) Zhongtang Yu, Assistant Professor, Dept. of Animal Sciences, Ohio State University (MFC microbiology), (3.) Lingying Zhao, Associate Professor, Dept. of Food, Agricultural & Biological Engineering, Ohio State University (MFC applications and project management). Graduate students: (1.) Carol Ann Mullin, (2.) Sarah Carver, (3.) Trent Bower. Undergraduate student: (1.) Winda Halim plus 55 students enrolled in FABE 225: Introduction to Food, Agricultural, and Biological Engineering. TARGET AUDIENCES: Researchers, undergraduate students, K-12 students. Efforts: (1.) Formal classroom instruction: MFC lab developed and presented in sophomore engineering class, FABE 225: Introduction to Food, Agricultural, and Biological Engineering. (2.) Informal instruction: Six events described in OUTPUTS section of this report PROJECT MODIFICATIONS: Not relevant to this project.

Impacts
Preliminary results of testing unique anaerobic microbial consortia in the MFCs at moderately thermophilic temperatures (50-60 degrees C) include the successful conversion of feedstocks such as cellulose and various waste paper products into bio-electricity. This is the first example of using waste paper directly in and MFC without pre-treatment of the substrate. It was found that white office copy paper was 75% degraded and newsprint was 50% degraded by the MFC microorganisms which simultaneously produced sustained electrical outputs.

Publications

• No publications reported this period

Progress 01/01/08 to 12/31/08

Outputs
OUTPUTS: OSU's Bio-energy / Microbial Fuel Cell team (an interdisciplinary group of agricultural / biological engineers, microbiologists, and animal scientists) earlier discovered that naturally occurring microorganisms in cow rumen fluid can anaerobically convert the chemical energy in cellulosic agricultural wastes directly into electric current by harnessing electrons from the microbes' electron transport mechanisms. The objective of our subsequent research has been to study the effect of different circuit resistances on the bacterial populations and their metabolism. Fuel cells were inoculated with a ruminal microbial consortium and operated for ten weeks with a circuit resistance of 20, 249, 480, or 1000 Ω. The maximum power output and coulombic efficiency were 40% and 7.4% higher, respectively, when the circuit resistance was 20 Ω rather than 1000 Ω. DGGE analysis of partial 16S rRNA genes showed clear differences between the planktonic and the anode biofilm populations at various circuit resistances. HPLC analysis revealed that electricity generation from cellulose was accompanied by production of acetic, propionic, butyric, isobutyric, valeric, isovaleric, and lactic acid, with acetic acid being the major one. The concentration of individual acids increased with increases in circuit resistance, resulting in relatively low coulombic efficiencies. The accumulation of SCFA at higher circuit resistances corresponded with lower power output. The newest aspect of this research is exploring the environmental and bio-energy benefits of cellulosic ethanol using biological pretreatment and hydrolysis reactions prior to fermentation. A two-step hydrolysis and fermentation process for producing cellulosic ethanol from sugarcane bagasse using dairy rumen microbes and yeast was designed. Focus was specifically on the crucial hydrolysis step, during which exposed cellulose is broken down by microbes into fermentable glucose sugars. It is hypothesised that given sufficient time, the rumen microbes used for this step will further convert these sugars into volatile fatty acids, which cannot be used directly for ethanol production by the yeast organisms. The optimum lab-scale hydrolysis period was found to be 84 hours, or 3.5 days, and laboratory analysis confirmed ethanol concentrations to be between 5 and 10 percent at this hydrolysis time length. Research presentations and papers included one peer reviewed journal article, one completed PhD dissertation, one presentation with an abstract, two invited presentations, and two poster presentations at national meetings. PARTICIPANTS: OSU Dept. of Microbiology: Dr. Olli Tuovinen; OSU Dept. of Animal Science: Dr. Burk Dehority, Dr. Zhongtang Yu, Dr. Mark Morrison TARGET AUDIENCES: Government agency personnel in environmental, natural resources, and energy departments; Bio-energy researchers; Consulting engineers, animal scientists, and microbiologists; Engineering educators; K-12 science educators PROJECT MODIFICATIONS: A new objective (12) was added. The newest aspect of this project is to explore the environmental and bio-energy benefits of cellulosic ethanol using biological pretreatment and hydrolysis reactions prior to fermentation. The objective was to design a two-step hydrolysis and fermentation process for producing cellulosic ethanol from sugarcane bagasse using dairy rumen microbes and yeast.

Impacts
In our microbial fuel cells (MFCs), rumen microorganisms generate electricity by anaerobic oxidation of cellulose and transfer of the resulting electrons to the fuel cell's anode. The potential impacts of this bioenergy research in microbial fuel cells and cellulosic ethanol include reduced dependence on non-renewable energy sources, treatment of recalcitrant lignocellulosic agricultural wastes, and reduction in greenhouse gas emissions.

Publications

• Rismani-Yazdi, Hamid, Sarah M. Carver, Ann D. Christy, Olli H. Tuovinen. 2008. Cathodic Limitations in Microbial Fuel Cells: An Overview. Journal of Power Sources 180(2): 683-694.
• Kim, Eun Kyoung, Ann D. Christy, and Julie Weatherington-Rice. 2008. Soil Textures that Support Fractures in the Glacially-Derived Materials of Ohio, Michigan, Iowa, and Wisconsin. Ohio Journal of Science 108(1): A-13.
• Rismani-Yazdi, Hamid. 2008. Bioconversion of Cellulose into Electrical Energy in Microbial Fuel Cells. Ph.D. Dissertation. The Ohio State University. June, 2008. 170 p. (advisor: A.D. Christy)
• Bethany Corcoran, Janell Henry, Reid Rice, Hamid Rismani-Yazdi, and Ann D. Christy. 2008. Cellulosic ethanol from sugarcane bagasse using rumen microorganisms. American Society of Agricultural and Biological Engineers Annual Meeting. ASABE Paper 08-5148. 27 p.(Published on CD (search at asae.frymulti.com))

Progress 01/01/07 to 12/31/07

Outputs
OUTPUTS: The status of this project is presented on an objective-by-objective basis. Objective 1: Glacial till field data from Ohio and across the Midwest plus the results from controlled fracturing experiments in the laboratory were analyzed to develop statistical models to predict the presence of fractures in various soil textures. Accomplishments for 2007 include one abstract and one completed PhD dissertation. Objectives 2 and 3: The ground water vulnerability assessment model, DRASTIC, was modified to better evaluate preferential flow effects in fractured glacial till. The goal was to make ground water pollution potential assessment more accurate and protective of water supplies, especially in preferential flow environments. Accomplishments for 2007 include one proceedings article. Objectives 4 through 9: No progress was made on these objectives this past year. Objective 10 (new in 2005): The Microbial Fuel Cell team (an interdisciplinary group of agricultural / biological engineers, microbiologists, and animal scientists) has discovered that naturally occurring microorganisms in cow rumen fluid can anaerobically convert the chemical energy in cellulosic agricultural wastes directly into electric current by harnessing electrons from the microbes' electron transport mechanisms. The team has successfully used them to power rechargeable batteries using only dairy waste as input. It was proven that it is possible to generate power densities of up to 55 mW per square meter without the addition of external redox mediators. Electricity generation involved anode-attached and suspended microorganisms which linked cellulose hydrolysis to anaerobic respiration and electrode reduction. The team is identifying the specific microorganisms responsible for electricity generation and optimizing these systems. Accomplishments for 2007 include one proceedings paper and one peer reviewed journal article. Objective 11 (new in 2006): In addition to her technical research program, Dr. Christy also engages in education research resulting in numerous refereed journal articles, proceedings papers, and over $400,000 in grant funding over the past 10 years. During 2007, this research effort resulted in two proceeding papers and one peer reviewed journal article. PARTICIPANTS: USDA-ARS in Columbus (specifically Drs. Norm Fausey and Barry Allred) OSU Dept. of Microbiology OSU Dept. of Animal Sciences Bennett and Williams Environmental Consultants Inc. Ohio Dept. of Natural Resources Solid Waste Authority of Central Ohio TARGET AUDIENCES: Government agency personnel in environmental, natural resources, and energy departments Consulting engineers, soil scientists, and geologists Land use planning professionals Engineering educators

Impacts
This research has developed easy-to-use methods to predict the existence of subsurface fractures based on soil texture analysis and has linked this to the DRASTIC planning tool that can guide local land use decisions to better protect ground water resources. This project is also exploring a new form of bioenergy, the microbial fuel cell. The potential impacts of the new microbial fuel cell research include reduced dependence on non-renewable energy sources, treatment of recalcitrant lignocellulosic agricultural wastes, reduction in greenhouse gas emissions and other environmental pollutants (e.g., as compared with coal or natural-gas generated electricity), and the potential founding of a bio-process technology industry based on agricultural waste products.

Publications

• Christy, A.D., and M. Lima. 2007. Teaching creativity and multidisciplinary approaches to engineering problem-solving. International Journal of Engineering Education 23(4): 636-644.
• Kim, Eun Kyoung, 2007. Use of soil texture analyses to predict fracturing in glacial tills and other unconsolidated materials. [DPhil dissertation, advisor: A.D. Christy]. Columbus (OH): The Ohio State University.
• Christy, Ann D., Julie Weatherington-Rice., Michael Angle, and Linda Aller. 2007. Field verification of ground water pollution potential in fractured environments using modified DRASTIC methodology. ASABE Paper 07-2143. Presented at 2007 ASAE Annual International Meeting. 6/17-20. Minneapolis, MN. (Published on CD (search at asae.frymulti.com) )
• Christy, Ann D., Margaret E. Owens, and Mary J. Faure. 2007. Student Portfolios, Business Communications, Engineering Poetry Contests, and Grading Multiple Drafts of Technical Writing Documents. ASABE Paper 07-8001. Presented at 2007 ASAE Annual International Meeting. 6/17-20. Minneapolis, MN. (Published on CD (search at asae.frymulti.com) )
• Kim, Eun Kyoung, Ann D. Christy, and Julie Weatherington-Rice. 2007. Use of soil texture laboratory analysis to predict fractures in Ohios glacial tills. Ohio Journal of Science 107(1): A-30.
• Rismani-Yazdi, Hamid, Ann D. Christy, and Olli H. Tuovinen. 2007. Power Output Assessment of Cellulose-Based Microbial Fuel Cells Operating under Different External Resistances. The 234th ACS National Meeting, Boston, MA, August 19-23, 2007. 2 p.(abstract at .)
• Rismani-Yazdi, Hamid, Ann D. Christy, Burk A. Dehority, Mark Morrison, Zhongtang Yu, and Olli H. Tuovinen. 2007. Electricity Generation from Cellulose by Rumen Microorganisms in Microbial Fuel Cells. Biotechnology and Bioengineering 97(6): 1398-1407.
• Ward, Andy D., Kerry Hughes Zwierschke, Carol Moody, and Ann D. Christy. 2007. Developing Sustainable Solutions for Impoverished Communities in South Africa: A Student Centered and Service Learning Capstone Design Experience. ASABE Paper 07-8018. Presented at 2007 ASAE Annual International Meeting. 6/17-20. Minneapolis, MN. (Published on CD (search at asae.frymulti.com) )

Progress 01/01/06 to 12/31/06

Outputs
The status of this project is presented on an objective-by-objective basis. Objective 1: Glacial till field data and controlled fracturing experiments in the laboratory were analyzed to develop statistical models to predict the presence of fractures in various soil textures. Objectives 2 and 3: The ground water vulnerability assessment model, DRASTIC, was modified to better evaluate preferential flow effects in fractured glacial till. The goal was to make ground water pollution potential assessment more accurate and protective of water supplies, especially in preferential flow environments. Accomplishments for 2006 include four abstracts and publication of the 2nd Special Issue of the Ohio Journal of Science, which included five refereed journal articles. Objectives 4 through 9: No progress was made on these objectives this past year. Objective 10 (new in 2005): The Microbial Fuel Cell team (an interdisciplinary group of agricultural / biological engineers, microbiologists, and animal scientists) has discovered that naturally occurring microorganisms in cow rumen fluid can anaerobically convert the chemical energy in cellolosic agricultural wastes directly into electric current by harnessing electrons from the microbes' electron transport mechanisms. The team has successfully used them to power rechargeable batteries using only dairy waste as input. It was proven that it is possible to generate power densities of up to 55 mW per square meter without the addition of external redox mediators. Electricity generation involved anode-attached and suspended microorganisms which linked cellulose hydrolysis to anaerobic respiration and electrode reduction. The team is working on identifying the specific microorganisms responsible for electricity generation and optimizing these systems. In a related project, landfill leachate from the Solid Waste Authority of Central Ohio (SWACO) was used to successfully power microbial fuel cells, albeit at lower power levels than the rumen fluid driven microbial fuel cells. Objective 11 (new this year): In addition to her technical research program, Dr. Christy also engages in education research resulting in numerous refereed journal articles, proceedings papers, and over $400,000 in grant funding over the past 10 years. During 2006, this research effort resulted in one proceeding paper and one accepted peer reviewed journal article which will be published in 2007.

Impacts
This research is developing methods to predict the existence of subsurface fractures and to build a planning tool that could guide local land use decisions to better protect ground water resources. This project is also exploring a new kind of landfill which biologically treats waste; the benefits of such a bioreactor landfill include increasing the capacity and working life of existing landfills, lessening the risk of off-site contaminant transport, reducing the health risk presented by landfills to neighboring communities, and reducing the number of new landfills that need to be constructed. The potential impacts of the new microbial fuel cell research include reduced dependence on non-renewable energy sources, treatment of recalcitrant lignocellulosic agricultural wastes, reduction in greenhouse gas emissions and other environmental pollutants (e.g., as compared with coal or natural-gas generated electricity), and the potential founding of a bio-process technology industry based on agricultural waste products.

Publications

• Christy, A. D., Weatherington-Rice, J., and Angle, M. 2006. Hydrogeologic settings in DRASTIC as modified for fractured till. Ohio Journal of Science 106(1):A48-A49.
• Frew, B., and Christy, A. D. 2006. Use of Landfill Leachate to Generate Electricity in Microbial Fuel Cells. American Society of Agricultural and Biological Engineers Annual Meeting. ASABE Paper 06-7064. 12 p.
• Graf, J. A., and Christy, A. D. 2006. Assessing perceptions of education: A case for increased interdisciplinarity. American Society of Agricultural and Biological Engineers Annual Meeting. ASABE Paper 06-8001. 16 p.
• Kim, E., and Christy, A. D. 2006. Soil texture analysis for predicting fractures in glacial till. GSA Abstracts with Programs Vol. 38, No. 4, p.19
• Kim, E., and Christy, A. D. 2006. Use of soil texture analysis to predict subsurface fracturing in glacial tills and other unconsolidated materials. Ohio Journal of Science 106(2):22-26.
• Kim, E., and Christy, A. D. 2006. Use of soil texture analysis to predict fractures in glacial tills. Ohio Journal of Science 106(1): A-49.
• Rismani-Yazdi, H., and Christy, A. D. 2006. Harvesting electricity from cellulose using rumen microbes in a microbial fuel cell. Ohio Journal of Science 106(1): A-53.
• Rismani-Yazdi, H., Christy, A. D., Dehority, B. A., and Tuovinen, O. H. 2006. A Microbial Fuel Cell Coupling Anaerobic Degradation of Agricultural Lignocellulose Wastes to Electricity Generation. ASABE Paper 06-7115. 7 p.
• Weatherington-Rice, J., Christy, A. D., and Angle, M. 2006. Further Explorations into Ohios Fractured Environment: Introduction to the Second Special Issue on Fractures in Ohios Glacial Tills. Ohio Journal of Science 106(2): 4-8.
• Weatherington-Rice, J., Christy, A. D., Angle, M., Aller, L., and Bennett, T. 2006. DRASTIC Hydrogeologic Settings Modified for Fractured Till: Part 1. Theory. Ohio Journal of Science 106(2):45-50.
• Weatherington-Rice, J., Christy, A. D., Angle, M., Gehring, R., and Aller, L. 2006. DRASTIC Hydrogeologic Settings Modified for Fractured Till: Part 2. Field Observations. Ohio Journal of Science 106(2):51-63.
• Weatherington-Rice, J., Hottman, A., Murphy, E., Christy, A. D., and Angle, M. 2006. Fractured tills, Ohio ground-water resources, and public policy considerations addressed by DRASTIC maps. Ohio Journal of Science 106(2):64-73.
• Christy, A. D., and Weatherington-Rice, J. 2006. Fractures in glacial till: How quickly can they form and how long can they persist? GSA Abstracts with Programs Vol. 38, No. 4, p.19.

Progress 01/01/05 to 12/31/05

Outputs
The status of this project is presented on an objective-by-objective basis. Objective 1. Standard methods are being developed for fracture studies in glacially -derived materials, including test pits, individual fracture mapping, and soil boring logging using a special data form. In 2005, new laboratory procedures were developed to test fracturing in glacially-derived soils under controlled conditions. 2. The relations between advances in the scientific understanding of fracture flow hydrogeology and legal policy was explored with legal ground water scholars and EPA policy personnel. In 2005, publications documenting recommended procedures to protect water resources in potentially sensitive environments have been submitted to a peer-reviewed journal. In addition, five extension fact sheets were developed and published on various topics of solid waste and landfills to be used when working with the public and elected officials. 3. A statistical model has been developed that would make it possible to predict the existence of hydraulically active fractures and build in a screening tool and/or protection strategy that would protect both the underlying aquifer from undesirable land-uses and would also allow local decision makers to plan for the placement of potentially contaminating land-uses in locations where they would be less harmful. The first paper resulting from this work has been submitted to a peer-reviewed journal. 4 No progress was made on this objective this past year. 5. The national survey of solid waste professionals to determine the state-of -practice in the industry with respect to bioreactor landfills has been performed. Publication is expected to be forthcoming this year. 6. Laboratory protocols to make scaled-down synthetic municipal solid waste (MSW) which accurately model the characteristics of MSW in the US including component percentages have been developed and will be published soon. 7. An investigation on how to design a leachate recirculation system to achieve the most uniform wetting of waste in a bioreactor landfill was performed. The results indicate that the combination of a deep, multiple level nested vertical well system and a surface trickle irrigation system give the most uniform wetting. Publication of results is expected this year. 8. No progress was made on this objective this past year. 9. No progress was made on this objective this past year. NEW OBJECTIVE: 10. The newest aspect of this project is to explore the environmental and bio-energy benefits of microbial fuel cells, an innovative technology that exploits the electron transport system of anaerobic microbes for the direct generation of electrical current . This research specifically focuses on electrical power production in microbial fuel cells using ligno-cellulosic agricultural wastes (e.g., corn stover, wheat straw, soiled livestock bedding) as their fuel sources. Preliminary results include power densities as high as 55 mW/m2 with cellulose as the sole energy source. Peer-reviewed publication of these early results may be expected soon.

Impacts
This research is developing methods to predict the existence of fractures and to build a planning tool that could guide local land use decisions to better protect ground water resources. This project is also exploring a new kind of landfill which biologically treats waste; the benefits of such a bioreactor landfill include increasing the capacity and working life of existing landfills, lessening the risk of off-site contaminant transport, reducing the health risk presented by landfills to neighboring communities, and reducing the number of new landfills that need to be constructed. The potential impacts of the new microbial fuel cell research include reduced dependence on non-renewable energy sources, treatment of recalcitrant ligno-cellulosic agricultural wastes, reduction in greenhouse gas emissions and other environmental pollutants (e.g., as compared with coal or natural-gas generated electricity), and the potential founding of a bio-process technology industry based on agricultural waste products.

Publications

• Hamid Rismani-Yazdi, Ann D. Christy, Burk A. Dehority, and Olli H. Tuovinen. 2005. Bioconversion of cellulose into electricity using rumen microorganisms as biocatalysts in a microbial fuel cell. 230th ACS National Meeting. American Chemical Society. 2 p. [published abstract].
• Hughes, Kerry L., Ann D. Christy, and Joseph E. Heimlich. 2005. Bioreactor Landfills. OSU Extension Fact Sheet CDFS-139-05. 3 p.
• Hughes, Kerry L., Ann D. Christy, and Joseph E. Heimlich. 2005. Landfills: Science and Engineering Aspects. OSU Extension Fact Sheet CDFS-137-05. 4 p.
• Hughes, Kerry L., Ann D. Christy, and Joseph E. Heimlich. 2005. Landfill Types and Liner Systems. OSU Extension Fact Sheet CDFS-138-05. 4 p.
• Hughes, Kerry L., Ann D. Christy, and Joseph E. Heimlich. 2005. Abandoned Dumps: Yesterday and Tomorrow. OSU Extension Fact Sheet CDFS-140-05. 3 p.
• Heimlich, Joseph E., Kerry L. Hughes, and Ann D. Christy. 2005. Integrated Solid Waste Management. OSU Extension Fact Sheet CDFS-106-05. 3 p.

Progress 01/01/04 to 12/31/04

Outputs
The status of this project is presented on an objective-by-objective basis. Objective 1. Standard methods are being developed for fracture studies in glacially -derived materials, including test pits, individual fracture mapping, and soil boring logging using a special data form. More work remains to be done. 2. The relations between advances in the scientific understanding of fracture flow hydrogeology and legal policy are being explored with legal ground water scholars and EPA policy personnel. Publications documenting recommended procedures to protect water resources in potentially sensitive environments should be forthcoming in the next year. 3. It is too soon to report progress on the expert system that would make it possible to predict the existence of hydraulically active fractures and build in a screening tool and/or protection strategy that would protect both the underlying aquifer from undesirable land-uses and would also allow local decision makers to plan for the placement of potentially contaminating land-uses in locations where they would be less harmful. Statistical analyses are currently being run on data from across the state, and the preliminary results are promising. 4. It is too soon to report progress on the permanent soil/geologic test pit. 5. The national survey of solid waste professionals to determine the state-of -practice in the industry with respect to bioreactor landfills has been performed. Publication is expected to be forthcoming this year 6. Laboratory protocols to make scaled-down synthetic municipal solid waste (MSW) which accurately model the characteristics of MSW in the US including component percentages have been developed; work on size distribution will follow. 7. An investigation on how to design a leachate recirculation system to achieve the most uniform wetting of waste in a bioreactor landfill was performed. The results indicate that the combination of a deep, multiple level nested vertical well system and a surface trickle irrigation system give the most uniform wetting. Publication is expected this year. 8. It is too soon to report progress on the role of non-hazardous, industrial wastewaters as alternate liquid amendments to bioreactor landfills and determine the optimal characteristics of a moisture source, identifying the best performers among candidate liquids. 9. It is too soon to report progress on a screening protocol using statistical and neural network modeling to predict performance of potential liquid waste amendments in bioreactor landfills.

Impacts
This research is developing methods to predict the existence of fractures and to build a planning tool that could guide local land use decisions to better protect ground water resources. This project is also exploring a new kind of landfill which biologically treats waste; the benefits of such a bioreactor landfill include increasing the capacity and working life of existing landfills, lessening the risk of off-site contaminant transport, reducing the health risk presented by landfills to neighboring communities, and reducing the number of new landfills that need to be constructed.

Publications

• Murphy, Timothy J. 2004. A Comparative Evaluation Of Liquid Infiltration Methods For Bioreactor Landfills. OSU Ph.D. dissertation (A.D. Christy, advisor). 405p.
• Weatherington-Rice, Julie. 2004. Fracture Occurrence and Ground Water Pollution Potential in Ohio's Glacial and Lacustrine Deposits: a Soils, Geologic, and Educational Perspective. OSU Phh.D. dissertation (George Hall and A.D. Christy, co-advisors). 400 p.
• Henslee, Brian. 2004. Biological fuel cell. OSU senior honors thesis (A.D. Christy, advisor).