Source: WASHINGTON STATE UNIVERSITY submitted to
MEASURING AND MODELING GASEOUS, PARTICULATES, AND ODOR EMISSIONS FROM LIVESTOCK OPERATIONS
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
TERMINATED
Funding Source
HATCH
Reporting Frequency
Annual
Accession No.
0205501
Grant No.
(N/A)
Project No.
WNP00630
Proposal No.
(N/A)
Multistate No.
(N/A)
Program Code
(N/A)
Project Start Date
Dec 1, 2009
Project End Date
Nov 30, 2014
Grant Year
(N/A)
Project Director
Ndegwa, P.
Recipient Organization
WASHINGTON STATE UNIVERSITY
240 FRENCH ADMINISTRATION BLDG
PULLMAN,WA 99164-0001
Performing Department
Biological Systems Engineering
Non Technical Summary
Over the last two decades, animal feeding operations (AFO's) have become larger and more concentrated in fewer geographical regions. This change in production patterns has resulted in huge volumes of manure in these regions, increasing tremendously the challenges of manure handling, storage, and use without endangering the environment. Air quality degradation presents a serious challenge to the sustainability and continued growth of the livestock industry. The long-term goal of this research initiative is to develop cost-effective technologies and methods to quantify and to mitigate gaseous, odor, and particulate emissions from AFO's.
Animal Health Component
0%
Research Effort Categories
Basic
15%
Applied
80%
Developmental
5%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
1410410202080%
1413499202010%
4033499202010%
Knowledge Area
141 - Air Resource Protection and Management; 403 - Waste Disposal, Recycling, and Reuse;

Subject Of Investigation
3499 - Dairy cattle, general/other; 0410 - Air;

Field Of Science
2020 - Engineering;
Goals / Objectives
The overall goal of this project is to develop a process-based model for the prediction of ammonia emissions from typical anaerobic lagoons or similar structures that hold or treat dairy wastewater. Specific objectives are: Develop a sub-model for the convective mass transfer of ammonia from dairy wastewater; Develop a sub-model for dissociation constant of ammonia in dairy wastewater; Conduct direct measurement of ammonia emissions from typical dairy wastewater lagoons; Perform validation of the process model in predicting ammonia emissions from anaerobic lagoons that treat dairy wastewaters; Perform sensitivity analyses to determine most critical parameters for ammonia emissions mitigation; Develop a user friendly computer interface for ammonia emissions model for dissemination to end-users
Project Methods
The work will determine the overall mass transfer coefficient of ammonia from liquid manure. Research will determine the dissociation constant equation of ammonia. Model validation will start with acquiring diverse ammonia emission data based on direct measurements of ammonia emissions at the Washington State University Knotts Dairy Farm over all four seasons of the year. Data will also be gathered from cooperating commercial dairy farms. The process model will be validated through statistical comparisons of model predictions with field measurements of ammonia emissions under similar conditions. Sensitivity analyses of the process model will be performed to determine the relative variations in ammonia emissions with respect to changes in the key model input variables. The work will conclude with development of a user-friendly computer interface for the improved process model to enhance its application and to encourage wide-spread adoption.

Progress 12/01/09 to 11/30/14

Outputs
Target Audience: Dairy producers, scientific community, environmental regulators and activists, staff of NRCS and Conservation Districts, extension personnel, and citizenries. Changes/Problems: The specific goal of this project was to model emissions from dairy wastewater. The project, however, was expanded to cover other aspects captured in the long term goal of our research program (i.e., to develop cost-effective technologies and methods to quantify and mitigate gaseous, odor, and particulate emissions from animal feeding operations). What opportunities for training and professional development has the project provided? Four PhD students and one MS student were involved and wrote their theses and dissertations from respective independent investigations conducted within this project. In addition, two Postdoctoral Fellows were trained under this project. How have the results been disseminated to communities of interest? Results from this project were presented, regularly, to stakeholders at various forums including: field days; regional, and national meetings and conferences; and via several forms of publications (e.g., scientific journals, conferences proceedings, bulletins, fact sheets, webinars, etc.). What do you plan to do during the next reporting period to accomplish the goals? This is the final report.

Impacts
What was accomplished under these goals? The number of journal and conference publications emanating from this project is testament to the project's contribution to advancement of knowledge and deepening of the tool-kit for mitigating, modeling, and quantification of emissions from livestock operations. In general, data from this project clearly demonstrated the environmental benefits of manure treatment via anaerobic digestion, which has the potential to spur wider adoption of this technology. Our modeling research component elucidated environmental and manure parameters not only important for process modeling of emissions but also for designing ammonia mitigation interventions. Another components of this project has developed improved methods for quantifying emissions from livestock housing and provided term emissions data from naturally ventilated barns, which are valuable for modeling emissions from these sources as well as for estimation of emission factors. Finally, this project investigated and documented practices adoptable bydairy farms with a manure-flush system to reduce respective emissions from barns.

Publications

  • Type: Conference Papers and Presentations Status: Other Year Published: 2013 Citation: Joo H., P. Ndegwa, J. Harrison, E. Whitefield, A. Heber, J. Ni. 2013. Potential air quality impacts of anaerobic digestion of dairy manure. From Waste to Worth: "Spreading" Science and Solutions. From Waste to Worth: "Spreading" Science and Solutions; April 1-5, 2013; Denver, Colorado.
  • Type: Conference Papers and Presentations Status: Other Year Published: 2013 Citation: Embertson N., G. Pruitt, H. Tahat, P. Ndegwa. 2013. Model of a Successful Regulatory-Industry Partnership to Address Air Emissions from Dairy Operations in Yakima, WA. From Waste to Worth: "Spreading" Science and Solutions. From Waste to Worth: "Spreading" Science and Solutions; April 1-5, 2013; Denver, Colorado.
  • Type: Conference Papers and Presentations Status: Other Year Published: 2013 Citation: F. Sun, J. H. Harrison, P. Ndegwa, H. S. Joo, E. Whitefield, K. Johnson. 2013. Ammonia emissions from eight types of dairy manure during storage. From Waste to Worth: "Spreading" Science and Solutions; April 1-5, 2013; Denver, Colorado.
  • Type: Conference Papers and Presentations Status: Other Year Published: 2012 Citation: F. Sun, J.H. Harrison, E. Whitefield, P. Ndegwa, H. S. Joo. 2012. Effect of manure source on ammonia emission on first day of application. ADAS. Joint Annual Meeting. Phoenix, AZ.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2012 Citation: Joo, H.J., P.M. Ndegwa, J. Harrison, E. Whitefield, A.J. Heber, J.Q. Ni. 2012. Emissions of ammonia and greenhouse gases (GHG) from anaerobically digested and undigested dairy manure systems. ASABE Annual Intl. Meeting. Paper number 121337962; Dallas, TX.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2012 Citation: Joo, H.S., P.M. Ndegwa, A.J. Heber, J.Q. Ni, W.W. Bogan, J.C. Ramirez-Dorronsoro, E. Cortus. 2012. Ammonia and hydrogen sulfide emissions from naturally ventilated free-stall dairy barns. ASABE Annual Inti. Meeting. Paper number 121337963; Dallas, TX.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2012 Citation: Page, L., J.Q. Ni, A.J. Heber, N.S. Mosier, X. Liu, H.S. Joo, H.S., P.M. Ndegwa. 2012. Effect of anaerobic digestion on volatile fatty acids in dairy manure. ASABE Annual Intl. Meeting. Paper number 121337674; Dallas, TX.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2011 Citation: Vaddella, K.V., P.M. Ndegwa, A. Jiang. 2011. A model for overall mass transfer coefficient of ammonia from dilute dairy manure slurries. ASABE Annual Intl. Meeting. Paper number 1110972; Louisville, KY.
  • Type: Conference Papers and Presentations Status: Other Year Published: 2011 Citation: Joo, H.S., P.M. Ndegwa, A.J. Heber, J.-Q. Ni, J.C. Ramirez-Dorronsoro, E.L. Cortus. 2011. Particulate matter emissions from naturally ventilated free-stall dairy barns. Air & Waste Management Association's Annual Conf. & Exhibition. Orlando, FL.
  • Type: Conference Papers and Presentations Status: Other Year Published: 2010 Citation: Vaddella, V.K., P.M. Ndegwa, H.S. Joo. 2010. A process-based model for ammonia emissions from storages of flushed dairy manure. Intl. Symp. on Air Quality and Manure Management for Agriculture Conf. Proc., Dallas, TX.
  • Type: Conference Papers and Presentations Status: Other Year Published: 2010 Citation: Vaddella, V.K., P.M. Ndegwa, H.S. Joo. 2010. A model for ammonia dissociation constant in dairy manure. ASABE Intl. Symp. on Air Quality and Manure Management for Agric. Conf. Proc., Dallas, TX.
  • Type: Conference Papers and Presentations Status: Other Year Published: 2010 Citation: Vaddella, V.K., P.M. Ndegwa, H.S. Joo. 2010. A process-based model for ammonia emissions from storages of flushed dairy manure. ASABE Annual Intl. Meeting. Pittsburgh, PA.


Progress 10/01/13 to 09/30/14

Outputs
Target Audience: Dairy producers/operators, environmental regulators, scientific community, graduate students, citizens. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Provided training for two PhD students, one MS student, and one postdoctoral fellow in 2014. How have the results been disseminated to communities of interest? Five peer refereed journal articles were published. Four presentations were made at national/international conferences. Six presentations at Regional/National/International meetings & conferences will be made in 2015. Another two to three peer refereed journal articles will be submitted/published in 2015. Two or three fact sheets will be prepared in 2015. What do you plan to do during the next reporting period to accomplish the goals? The project has terminated as of 11/30/2014.

Impacts
What was accomplished under these goals? Research results have been published in peer refereed journals, presented in professional conferences (for scientific community), and also in other non-professional meetings (for other stakeholders including: dairy producers, regulators, citizens, etc.).

Publications

  • Type: Journal Articles Status: Published Year Published: 2014 Citation: Sun, F., J.H. Harrison, P.M. Ndegwa, K. Johnson. 2014. Effect of manure treatment on ammonia emissions during storage under ambient environment. Water, Air, & Soil Pollution Water, Air, & Soil Pollution 225(9).
  • Type: Journal Articles Status: Published Year Published: 2014 Citation: Sun, F., J.H. Harrison, P.M. Ndegwa, K. Johnson. 2014. Effect of manure treatment on ammonia and greenhouse gases emissions following surface application. Water, Air, & Soil Pollution 225: 1923.
  • Type: Journal Articles Status: Published Year Published: 2014 Citation: Koirala, K., P.M. Ndegwa, H.S. Joo, C. Frear, C.O. Stockle, J.H. Harrison. 2014. Effects of suspended solids characteristics and concentration on ammonia emission process from liquid dairy manure. Trans. ASABE 57(2): 661-668.
  • Type: Journal Articles Status: Published Year Published: 2014 Citation: Page, L.H., J.-Q. Ni, A.J. Heber, N.S. Mosier, X. Liu, H.-S. Joo, P.M. Ndegwa, J.H. Harrison. 2014. Characteristics of volatile fatty acids in stored dairy manure before and after anaerobic digestion. Biosystems Engineering 118: 16-28.
  • Type: Journal Articles Status: Published Year Published: 2014 Citation: Joo, H.S., P.M. Ndegwa, A.J. Heber, B.W. Bogan, J.-Q. Ni, E.L. Cortus, J.C., Ramirez-Dorronsoro. 2014. A direct measurement of gaseous emissions from naturally ventilated dairy barns. Atmospheric Environment 86: 176186
  • Type: Journal Articles Status: Accepted Year Published: 2014 Citation: Joo H., P. Ndegwa, A. Heber, J. Ni, B. Bogan, J. Ramirez-Dorrons, E. Cortus. Greenhouse gas emissions from naturally ventilated freestall dairy barns. Atmospheric Environment. In press.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2014 Citation: Neerackal G., H. Joo, P. Ndegwa, J. Harrison. Manure-pH Management for Mitigating Ammonia Emissions from Manure-Flush Dairy Barns. 2014. ASABE Annual International Conference Proceedings. ASABE Annual Meeting; July 13-16; Montreal, Canada.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2014 Citation: Joo H., P. Ndegwa, A. Heber, B. Bogan, J. Ni, E. Cortus, J. Ramirez-Dorrons. A direct Method of Measuring Gaseous Emissions from Naturally Ventilated Dairy Barns. 2014. ASABE Annual International Conference Proceedings. ASABE Annual Meeting; July 13-16; Montreal, Canada.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2014 Citation: Harrison J., J. Jarrett, Y. Chen, L. Vanwieringen, B. Chalupa, F. Sun, P. Ndegwa, D. Wight, H. S Joo. Effect of strategic ration balancing with use of Prolak and MetaboLys on the efficiency of milk protein production and environmental impact. 2014. J Dairy Sci. ADSA Annual Meeting; July 7 -10, 2014; KS City.
  • Type: Conference Papers and Presentations Status: Submitted Year Published: 2014 Citation: Wang X., H. Joo, G. Neerackal, P. Ndegwa. Indirect versus Direct Methods for Ventilation Rates Measurement in Naturally Ventilated Dairy Barns. Waste to Worth Conference - Advancing Sustainability in Animal Agriculture. Waste to Worth Conference - Advancing Sustainability in Animal Agriculture; March 30 - April 3, 2015; Seattle, Washington.
  • Type: Conference Papers and Presentations Status: Submitted Year Published: 2014 Citation: Wang X., H. Joo, G. Neerackal, P. Ndegwa, J. Harrison. Passive Samplers for Monitoring Ammonia Emissions in Naturally Ventilated Dairy Barns. submitted. ASABE Annual International Conference Proceedings. ASABE Annual Internation Conference; July 26 - 29; New Orleans, LA.
  • Type: Conference Papers and Presentations Status: Submitted Year Published: 2014 Citation: Wang X., H. Joo, G. Neerackal, P. Ndegwa, L. YU, Y. Ma, H. Liu. A Simplified Direct Method for Determining Ventilation Rates in Naturally Ventilated Dairy Barns. submitted. ASABE Annual International Conference Proceedings. ASABE Annual Internation Conference; July 26 - 29; New Orleans, LA.


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

Outputs
Target Audience: 1. Scientist, Engineers, and Consultants involved in management of livestock manures. 2. Livestock producers or operators. 3. Air Quality Regulators and Legislators. 4. Students and Future Scientist and Engineers in this Field or Area. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Data from research activities demonstrate the environmental benefits (e.g., reduction of potential for odor generation and greenhouse gases emissions) during post-storage AD effluent which, has the potential to spur wider adoption of the AD technology in dairy operations seeking to further responsible environmental stewardship and also reduce push-back from communities living next to dairies. On the other hand, the increased emission of NH3 from post-AD effluent storages may call for more stringent strategies for mitigating ammonia emissions from stored AD effluent. Our modeling research elucidated how manure characteristics as well as manure treatment via anaerobic digestion affect the ammonia volatilization mechanism. The results will enhance models for determining emissions and also the development of strategies for mitigating ammonia emissions from manure storage or similar manure storage structures. Our research on mitigation of gaseous emissions from dairy barns indicated potential adjustments necessary in the management of manure in dairy barns to mitigate ammonia, hydrogen sulfide, and greenhouse gas emissions from dairy operations. In addition, this research also highlighted some management approaches which will not work for dairy operations. How have the results been disseminated to communities of interest? These research activities resulted in the publication of five articles in refereed journals.Our research team made a total of eight presentations at national and international conferences and meetings. What do you plan to do during the next reporting period to accomplish the goals? We will continue our research along the same themes during the next reporting period.

Impacts
What was accomplished under these goals? Our research in 2013 was focused on three main goals: (a) Impact of Anaerobic digestion (AD)and Solids-Liquid Separation on Air Quality: Research on the effect of AD of dairy manure on the emissions of ammonia (NH3) and greenhouse gases (GHG) during manure storage and also in subsequent land applications was continued in 2013. Data collected corroborated earlier preliminary findings, which indicated significantly higher fluxes of GHG (CO2, N2O, and CH4) from land applied non-AD manure than from land applied AD manure; while injection of non-AD manure seemed to further increase CH4 flux from the soil. Similar emissions of GHG from the lagoon holding AD manure were significantly lower than from the lagoon holding non-AD manure. In contrast, more NH3 emissions were observed from the pond treating AD manure than from the pond treating non-AD manure. Further research showed that, NH3 emissions were influenced by increased dissociation of ammonium rather than increased TAN concentrations upon AD of manure. These data, in general, demonstrate key environmental benefits for AD of manure prior to its field application but also indicate potential liability from increased emission of NH3 from manure storages. The results also indicated less odor problems from AD manure as well as reduced potential for odor generation during subsequent storage of AD-manures. In addition, solids-liquid separation further reduced the potential for odor production from the separated liquid stream. (b) Measurement and Modeling Air Emissions: Quantification of emissions from dairy operations is essential for both mitigation and regulations purposes. Direct measurement of NH3 emissions from manure holding systems can be complicated and expensive; however, process-based emission models can provide a cost-effective alternative for estimating NH3 emissions. Two important parameters for process-based modeling are the dissociation of ammonium ion (NH4 ) and the overall NH3 mass transfer coefficient (KOL). Studies were conducted to elucidate how these two parameters are affected by manure characteristics and by anaerobic digestion of manure. Result indicated significantly higher pH, TAN, ionic strength (IS) and viscosity in AD manure compared to UD manure. The KoL and a, under identical conditions, were significantly higher for AD manure than for UD manure (p>0.05). Coupled with significantly higher TAN concentration in the AD manure, these findings indicate that AD of dairy manure significantly exacerbates ammonia volatilization from exposed liquid dairy manure surfaces. Another study focused on the effect of suspended solids characteristics on the ammonia volatilization mechanisms. Results indicated that, other than the concentration of the suspended solids (SS), the differences in the SS characteristics were not significant in the ammonia volatilization process. A third study along this theme investigated the dynamics of particulate matter emissions from naturally ventilated dairy barns. The mean respective emission rates of PM2.5, PM10, and TSP for the two barns ranged between 1.6-4.0, 11.9-15.0, and 48.7-52.5 g d-1 cow-1, indicating similar emissions from the two barns. Total suspended particulate (TSP) concentrations in spring and autumn were relatively higher than those in summer. The concentrations of PM2.5 and PM10 increased with ambient air temperature, whereas concentrations of TSP increased with cattle activity. (c) Mitigations of emissions from dairy operations: In 2013, we continued with evaluations of three common manure management practices including: manure flushing frequency; alternating manure flushing with manure vacuuming; and high-level solids-liquid separation. Our results for 2013 compared well with the 2012 results. Doubling flushing events by replacing the 6 h by 3 h flushing events did not show any significant advantages on emissions mitigations. On the contrary, significantly more H2S emissions were observed with this change. Alternating flushing and scraping every 6 h resulted in lower emissions of CO2 and H2S (13% and 22%, respectively) than normal flushing every 6 h. Other emissions were not significantly different. The effect of using cleaner water from screw press and centrifuge for manure flushing was significantly better for mitigating emissions than the flush water from a secondary lagoon. Reductions of emissions for all the five gases monitored were: 37% for NH3, 16% for CO2, 28% for N2O, 4% for CH4, and 15% for H2S.

Publications

  • Type: Conference Papers and Presentations Status: Published Year Published: 2013 Citation: Joo H., P. Ndegwa, J. Harrison, E. Whitefield, A. Heber, J. Ni. 2013. Potential air quality impacts of anaerobic digestion of dairy manure. From Waste to Worth: "Spreading" Science and Solutions. From Waste to Worth: "Spreading" Science and Solutions; April 1-5, 2013; Denver, Colorado.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2013 Citation: Embertson N., G. Pruitt, H. Tahat, P. Ndegwa. 2013. Model of a Successful Regulatory-Industry Partnership to Address Air Emissions from Dairy Operations in Yakima, WA. From Waste to Worth: "Spreading" Science and Solutions. From Waste to Worth: "Spreading" Science and Solutions; April 1-5, 2013; Denver, Colorado.
  • Type: Theses/Dissertations Status: Published Year Published: 2013 Citation: Kedar Koirala. Characterization of Ammonia Volatilization from Liquid Dairy Manure.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2013 Citation: Joo H., P. Ndegwa, A. Heber, J. Ni, B. Bogan, J. Ramirez-Dorrons, E. Cortus. 2013. Emissions of greenhouse gases from naturally ventilated freestall dairy barns. Paper number 131593425, ASABE Annual International Conference, July 21-24; Kansas City, Missouri.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2013 Citation: Wang X., H. S Joo, G. Neerackal, P. Ndegwa, J. Harrison, A. Heber, J. Ni. 2013. Effects of anaerobic digestion and application methods on ammonia emission from land applied dairy manure. Paper number 131593443, ASABE Annual International Conference, July 21-24; Kansas City, Missouri.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2013 Citation: Neerackal G., H. S Joo, X. Wang, P. Ndegwa, J. Harrison, A. Heber, J. Ni. 2013. Impacts of anaerobic digestion and solids separation on ammonia emissions from stored dairy manure. Paper number 131593586, 2013 ASABE Annual International Conference; July 21-24; Kansas City, Missouri.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2013 Citation: Koirala K., H. Joo, C. Frear, J. Harrison, C. Stockle, P. Ndegwa. 2013. Influence of suspended solids characteristics on ammonia volatilization mechanism from liquid dairy manure. Paper number 131593399, ASABE Annual International Conference; July 21-24; Kansas City, Missouri.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2013 Citation: Joo H., P. Ndegwa, G. Neerackal, X. Wang, J. Harrison, J. Neibergs. 2013. Mitigation of ammonia, hydrogen sulfide, and greenhouse gases emissions from naturally ventilated dairy barns. Paper number 131593447, ASABE Annual International Conference; July 21-24; Kansas City, Missouri.
  • Type: Journal Articles Status: Accepted Year Published: 2014 Citation: Joo, H.S., P.M. Ndegwa, A.J. Heber, B.W. Bogan, J.-Q. Ni, E.L. Cortus, J.C., Ramirez-Dorronsoro. 2014. Measurement of Gaseous Emissions from Naturally Ventilated Dairy Barns. Atmospheric Environment.
  • Type: Journal Articles Status: Published Year Published: 2013 Citation: Page, L.H., J.-Q. Ni, A.J. Heber, N.S. Mosier, X. Liu, H.-S. Joo, P.M. Ndegwa, & J.H. Harrison. 2013. Characteristics of volatile fatty acids in stored dairy manure before and after anaerobic digestion. Biosystems Engineering 118: 16-28. http://dx.doi.org/10.1016/j.biosystemseng.2013.11.004
  • Type: Journal Articles Status: Published Year Published: 2013 Citation: Koirala, K., P.M. Ndegwa, H.S. Joo, C. Frear, C.O. Stockle, J.H. Harrison. 2013. Impact of anaerobic digestion of liquid dairy manure on ammonia volatilization process. Transactions of the ASABE 56(5): 1959-1966.
  • Type: Journal Articles Status: Published Year Published: 2013 Citation: Joo, H.S., P.M. Ndegwa, A.J. Heber, J.-Q. Ni, B.W. Bogan, J.C. Ramirez-Dorronsoro, E.L. Cortus. 2013. Particulate matter dynamics in naturally ventilated freestall dairy barns. Atmospheric Environment. 69: 182-190.
  • Type: Journal Articles Status: Published Year Published: 2013 Citation: Vaddella, V.K., P.M. Ndegwa, A. Jiang, J.L. Ullman. 2013. Mass transfer coefficients of ammonia for liquid dairy manure. Atmospheric Environment 66: 107-113.


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

Outputs
OUTPUTS: Our research in 2012 was focused on three main themes:- (a) Impact of Anaerobic digestion (AD) on Air Quality: Research on the effect of AD of dairy manure on the emissions of ammonia (NH3) and greenhouse gases (GHG) during manure storage and also in subsequent land applications was continued in 2012. Data indicated significantly higher fluxes of GHG (CO2, N2O, and CH4) from land applied non-AD manure than from land applied AD manure. In addition, injection of non-AD manure seems to further increase CH4 flux from the soil. Emissions of GHG from the lagoon holding AD manure were significantly lower than from the lagoon holding non-AD manure. In contrast, more NH3 emissions are emitted from the pond treating AD manure than from the pond treating non-AD manure. As in the previous year, the data demonstrated key environmental benefits for AD of manure prior to its field application but potential liability from increased emission of NH3 from storages. The results also indicated less odor problems from AD manure and also lower potential for odor production during subsequent storage of AD-manures. (b) Modeling Air Emissions: Direct measurement of NH3 emissions from manure holding systems can be complicated and expensive; however, process-based emission models can provide a cost-effective alternative for estimating NH3 emissions. Two important parameters for process-based modeling are the dissociation of ammonium ion (NH4+) and the overall NH3 mass transfer coefficient (KOL). Studies were conducted to elucidate how these two parameters are affected by manure characteristics and by anaerobic digestion of manure. Result indicated significantly higher pH, TAN, ionic strength (IS) and viscosity in AD manure compared to UD manure. The KoL and α, under identical conditions, were significantly higher for AD manure than for UD manure (p>0.05). Coupled with significantly higher TAN concentration in the AD manure, these findings indicate that AD of dairy manure significantly exacerbates ammonia volatilization from exposed liquid dairy manure surfaces. (c) Mitigations of emissions from dairy operations: In 2012, three Best Management Practices (BMP) were evaluated: manure flushing frequency; alternating manure flushing with manure vacuuming; and high-level solids-liquid separation. Doubling flushing events by replacing the 6 h by 3 h flushing events did not show any significant advantages on emissions mitigations. On the contrary, significantly more H2S emissions were observed with this change. Alternating flushing and scraping every 6 h resulted in lower emissions of CO2 and H2S (13% and 22%, respectively) than normal flushing every 6 h. Other emissions were not significantly different. The effect of using cleaner water from screw press and centrifuge for manure flushing was significantly better for mitigating emissions than the flush water from secondary lagoons. Reductions of emissions for all the five gases monitored were: 37% for NH3, 16% for CO2, 28% for N2O, 4% for CH4, and 15% for H2S. PARTICIPANTS: Pius Ndegwa, Kedar Koirala, HungSoo Joo, Xiang Wang, George Neraackal, Laura Page, Anping Jiang, Venkata Vaddella, Albert J. Heber, Jiqin Ni, Juan C. Ramirez-Dorronsoro, Erin L. Cortus, William Bogan, Elizabeth Whitefield, Joseph H. Harrison, Fei Sun. TARGET AUDIENCES: Dairy farmers, air-quality personnel PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
1. Our research illustrates the environmental benefits (reduction of odor and greenhouse gases emissions) for AD of manure prior to its field application. This has the potential to spur wider adoption of the AD technology in dairy operations and potential liability from increased emission of NH3 from storages, which may require increased strategies for mitigating ammonia emissions from the AD effluent. 2. Our modeling research elucidated how manure characteristics as well as manure treatment via anaerobic digestion affect the ammonia volatilization mechanism. These results are critical to the development of strategies for mitigating ammonia emissions from manure storage and similar manure storage structures. 3. Our research on mitigation of gaseous emissions from dairy barns indicated potential adjustment necessary to mitigate ammonia emissions from dairy operations. In addition, this research also highlighted some approaches which will not work for dairy operations. 4. Training of 4 graduate students and one post-doctoral fellow. 5. Publications of two articles in refereed journals from data obtained in our research activities. 6. Five presentations at national and international conferences and meetings of results from our research activities.

Publications

  • Vaddella V., P.M.Ndegwa, J.Ullman, A.Jiang 2012. Mass transfer coefficients of ammonia for liquid dairy manure. Atmospheric Environment. 66:107-113.
  • Joo H.S., P.M.Ndegwa, A.J.Heber, J.-.Ni, B.W.Bogan, J.C.Ramirez-Dorrons, E.L.Cortus 2012. Particulate matter dynamics in naturally ventilated freestall dairy barns. Atmospheric Environment. 69:182-190.


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

Outputs
OUTPUTS: Our research in 2011 was focused on three main themes; their respective outputs are briefly outlined below. I - Impact of Anaerobic Digestion on Air Quality - The effect of anaerobic digestion (AD) of dairy manure on the emissions of ammonia (NH3) and greenhouse gases (GHG) during manure storage and also in subsequent land applications were evaluated. Preliminary results indicate significantly higher fluxes of GHG (CO2, N2O, and CH4) from land applied non-AD manure than from land applied AD manure. In addition, injection of non-AD manure seems to further increase CH4 flux from the soil. More than a 50% increase in emissions of CO2 and CH4 was observed during the first 3 days after the was manure applied. Emissions of GHG from the lagoon holding AD manure were significantly lower than from the lagoon holding non-AD manure. In contrast, the reverse was observed for NH3 emissions. This data demonstrate some environmental benefits for AD of manure prior to its field application but also some potential increased emission of NH3 from storages. The potential production of volatile fatty acids (VFA) during storage of AD and non-AD dairy manure was also evaluated over a three month period. Significant differences in VFA concentrations between the digested and non-digested manure were observed. The results of this study further demonstrated that digestion of dairy manure results in production of VFA, which translates into less odor generation from digested-manure storage. II - Modeling Air Emissions - Direct measurement of NH3 emissions from manure holding systems can be complicated and expensive; however, process-based emission models can provide a cost-effective alternative for estimating NH3 emissions. Two important parameters for process-based modeling are the dissociation of the ammonium ion (NH4+) and the overall NH3 mass transfer coefficient (KOL). Studies were conducted to elucidate how these two parameters are affected by manure characteristics and manure pretreatments. Our results emphasize the need for: (i) inclusion of both the TS concentration and the temperature in models of Kd and KOL in liquid dairy manure, and (ii) covering the entire range of TS and temperature encountered in the region where the model will be used. Our research provides a suite of Kd and KOL values applicable to liquid dairy manure and the establishment of empirical models that yield accurate Kd and KOL estimates under a range of conditions for use in process-based models that provide valuable tools for predicting NH3 emissions from dairy operations. This research also indicates that, although total suspended solids impact ammonia volatilization, the size of suspended solids does not have a significant effect on ammonia loss process. III - National Air Emissions Monitoring Study (NAEMS) - This past year we continued mining the large volume of data obtained from this study, primarily focusing on refining data processing procedures. As a result, we now have a refined data processing system that will enable completion of several peer refereed publications from this work. In addition, we wrote three conference publications for presentation this year or in 2012. PARTICIPANTS: Washington State University, Pullman: Pius M. Ndegwa (PI), J. Richard Alldredge, Anping Jiang, Hung Soo Joo, Marvin J. Pitts, Jeffrey L. Ullman, and Venkata K. Vaddella. Washington State University, Puyallup: Joseph H. Harrison; Elizabeth M. O'Rourke Whitefield, Extension Coordinator. Pennsylvania State University, University Park: Alexander N. Hristov. Purdue University, West Lafayette, IN: Erin L. Cortus, Albert J. Heber, Ji-Qin Ni, Juan C. Ramirez-Dorronsoro. Virginia Tech, Blacksburg: Jactone Arogo Ogejo. TARGET AUDIENCES: Livestock producers, air quality regulators, researchers, livestock extension agents, and air quality consultants. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
1. Our research clearly demonstrates the environmental benefits of reduced odor and greenhouse gas emissions by the anaerobic digestion of manure prior to its field application; and AD also shows some potential in the increased emission of NH3 from storages. This has the potential to spur a wider adoption of the AD technology in dairy operations. 2. Our modeling effort elucidates important environmental and manure characteristics that are important in the effort to develop strategies to mitigate ammonia emissions from manure storage and similar manure storage structures. 3. Our modeling research effort also provides a suite of ammonium dissociation (Kd) and overall mass transfer (KOL) values applicable to the volatilization process of ammonia for liquid dairy manure and the development of empirical models that yield accurate Kd and KOL estimates under a range of conditions for use in process-based models for predicting NH3 emissions from dairy operations. 4. Our NAEMS research effort in 2011 has also resulted in a more robust method of computing the ventilation rates of naturally-ventilated dairy barns, commonly found in the Western U.S. 5. The publication of four refereed journal articles has helped disseminate the findings of our research.

Publications

  • Hristov, A.N., Hanigan, M., Cole, A., Todd, R., McAllister, T.A., Ndegwa, P.M., and Rotz, A. 2011. Review: Ammonia emissions from dairy farms and beef feedlots. Can J Anim Sci. 91(1):1-35.
  • Ndegwa, P.M., Hristov, A.N., and Ogejo, J.A. 2011. Chapter 6. Ammonia Emission from Animal Manure: Mechanisms and Mitigation Techniques. IN: Environmental Chemistry of Animal Manure (Z. He, Ed). Nova Science Publishers, Hauppauge, NY. pp. 107-151.
  • Vaddella, V.K., Ndegwa, P.M., and Jiang, A. 2011. An Empirical model for ammonium ion dissociation in liquid dairy manure. Trans ASABE. 54(3):1119-1126.
  • Vaddella, V.K., Ndegwa, P.M., and Joo, H.-S. 2011. Ammonia loss from simulated post-collection storage of scraped and flushed dairy-cattle manure. Biosyst Eng. 110(3):291-296.


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

Outputs
OUTPUTS: (A). Ammonia Emissions and Emissions Mitigations: This research component focused on three aspects, namely: (i) updated review of ammonia emissions from animal feeding operations, (ii) impact of separation of animal excretions on ammonia emissions, and (iii) mitigation of ammonia emissions through dietary changes. A book chapter and a review article (in the Journal of Environmental Quality) were submitted for publication based on research work on activity (i). Although this method has proven to reduce ammonia emissions in confined dwelling for animals, our current study indicated no advantage of separating urine and feces prior to storage for reasons of reducing ammonia emissions during post-separation storage. The output from the activity (ii) resulted in a refereed journal publication, while the activities outlined in (iii) resulted in two peer refereed publications (in the Journal of Dairy Science). The main conclusions from these studies were: (a) increasing dietary concentrate in the diets of lactating cows was not a successful strategy for mitigation of ammonia emissions from excreted manure, and (b) low crude protein content in the diet decreased irreversible loss of ruminal ammonia, which consequently resulted in reduced potential for ammonia loss from excreted manure without affecting cow performance. (B). Odor and Other Emissions: This research aspect focused on processing and publication of data collected in previous years related to: (i) anaerobic digestion, and (ii) national air emissions monitoring study (NAEMS). Activity (i) resulted in one peer refereed publication (in Bioprocess and Biosystems Engineering). The results from this study demonstrated that use of granules-inocula could reduce the startup of anaerobic digestion by up 25%. Activity (ii), on the other hand, produced a report for NAEMS, which was submitted to EPA in September 2010. This year we will embark on peer refereed publications of the NAEMS data from activity (ii). PARTICIPANTS: Washington State University, Pullman: Pius M. Ndegwa (PI), J. Richard Alldredge, Hung Soo Joo, Marvin J. Pitts, Jeffrey L. Ullman, and Venkata K. Vaddella. Pennsylvania State University, University Park: Alexander N. Hristov. Purdue University, West Lafayette, IN: William W. Bogan, Erin L. Cortus, Albert J. Heber, Ji-Qin Ni, Juan C. Ramirez-Dorronsoro. University of Idaho, Moscow: Matthew Angle, Christopher Schneider, Mike Vander Pol, and Shah Zaman. Virginia Tech, Blacksburg: Jactone Arogo Ogejo. TARGET AUDIENCES: Livestock producers, air quality regulators, researchers, livestock extension agents, and air quality consultants. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
1. The published book chapter and review article on ammonia emissions from Confined Animal Feeding Operations (CAFO) provides stakeholders with necessary information to manage and regulate ammonia emissions from CAFOs. 2. Publication of these three refereed journal articles expands the tool box of ammonia emission mitigation strategies providing CAFO operators with a wider selection of methods of reducing ammonia emissions. 3. Enhanced anaerobic digestion not only saves CAFO money but also improves mitigation of odor emissions.

Publications

  • Angle, M., Hristov, A.N., Zaman, S., Schneider, C., Ndegwa, P.M., and Vaddella, V.K. 2010. Effect of dietary concentrate on rumen fermentation, digestibility, and nitrogen losses in dairy cows. J. Dairy Sci. 93(9):4211-4222.
  • Angle, M., Hristov, A.N., Zaman, S., Schneider, C., Ndegwa, P.M., and Vaddella, V.K. 2010. The effect of ruminally degraded protein on rumen fermentation and ammonia losses from manure in dairy cows. J Dairy Sci. 93(4):1625-1637.
  • Ndegwa, P.M., Hristov, A.N., and Arogo Ogejo, J. 2011. Ammonia Emission from Animal Manure: Mechanisms and Mitigation Techniques. IN: Environmental Chemistry of Animal Manure. Zhongqi He (Ed.). Nova Science Publishers, Hauppauge, NY. ISBN: 978-1-61209-222-5.
  • Pandey, P.K., Ndegwa, P.M, Alldredge, J.R., Pitts, M.J., and Soupier, M.L. 2010. Modeling effects of granules on the start-up of anaerobic digestion of dairy wastewater with Langmuir and extended Freundlich equations. Bioprocess Biosystems Eng. 33(7):833-845.
  • Vaddella, V.K., Ndegwa, P.M., Joo, H.S., and Ullman, J.L. 2010. Impact of separating dairy cattle excretions on ammonia emissions. J Environ Qual. 39:1807-1812.


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

Outputs
OUTPUTS: Emissions Mitigation Studies: Efforts on this research emphasis focused on strategies of manure post-collection handling and storage to mitigate ammonia emissions in dairy facilities. In one study, ammonia loss from simulated post-collection storage of flushed manure was compared to that from simulated storage of scraped manure. This study indicated preference for the manure flushing system over the manure scraping system for mitigation of ammonia emissions from manure post-collection storages. In another study, ammonia loss was evaluated from model-scale storages of separated urine and feces. This study indicated no advantage of separating urine and feces prior to storage for reasons of reducing ammonia emissions during post-separation storage. In addition, further studies were conducted to elucidate impacts of diet modifications on reduction of ammonia emissions and methane from livestock facilities. Diet modification studies indicated that increased concentrate proportion in the diet of dairy cows resulted in reduced ruminal ammonia concentration and enhanced ammonia utilization for milk protein synthesis. However, these effects did not reduce urinary N losses and only marginally improved milk N efficiency. The studies also indicated that reduction in dietary crude protein concentration effectively reduced ammonia emissions from cattle manure. Measurements or Evaluation of Air Emissions: One component of this research effort was the development of an improved process-based model for estimating ammonia emissions from dairy manure storages. To achieve our objective of an improved ammonia emissions model, sub-models of two critical coefficients were developed and incorporated into the generic process model. Limited data collected directly from a dairy wastewater lagoon were used for model validation. This approach resulted in a process model with higher accuracy than previous models. The other component of this research effort involved continued monitoring of air quality (hydrogen sulfide, ammonia, methane, nitrous oxide, carbon dioxide, particulate matter, and volatile organic compounds) in a typical free-stall dairy operation under the auspices of the National Air Emissions Monitoring Study (NAEMS). The main activities involved data collection and maintenance of the equipment at the project site near Sunnyside, Washington. This latter research project was concluded in November and we are currently analyzing the data. PARTICIPANTS: Washington State University, Pullman: Pius M. Ndegwa (PI), Hung soo Joo, and Venkata K. Vaddella. Cornell University, Ithaca, NY: Curt A. Gooch. Pennsylvania State University, University Park: Alexander N. Hristov. Purdue University, West Lafayette, IN: William W. Bogan, Erin L. Cortus, Richard H. Grant, Albert J. Heber, Ji-Qin Ni, Juan C. Ramirez-Dorronsoro. University of California, Davis: Frank M. Mitloehner. University of Idaho, Moscow: Matthew Angle, Larry Campbell, Christopher Schneider, Mike Vander Pol, and Shah Zaman. University of Minnesota, St. Paul: Larry Jacobson. University of Missouri, Columbia: James Swearengen, D.V.M. U.S. Geological Survey, Menlo Park, CA: Steven Silva. Virginia Tech, Blacksburg: Jactone Arogo Ogejo. TARGET AUDIENCES: Livestock producers, practitioners, consultants, legislators, scientists, and other stakeholders. PROJECT MODIFICATIONS: This projected has been significantly revised for renewal for another five years. The core research agenda, however, has not changed.

Impacts
1. Producers can now objectively select a manure flushing system over a manure scrape system if the goal is to reduce ammonia emissions. 2. Engineering Practitioners, Scientists, and Producers can now objectively decide whether pursuing development of urine-feces separation technologies for mitigating ammonia emissions is a worthy pursuit. 3. Our studies on diet modification further demonstrated that reduced dietary crude protein effectively mitigates ammonia emissions from dairy manure storages. 4. Our ammonia emissions process-based method incorporating empirically derived coefficients improved the model's accuracy from a normalized mean error (NME) of 120% (using theoretically derived coefficients) and 21% (using generic empirically derived coefficients) to NME of 15% (using site-specific empirically derived coefficients). This approach will probably be adopted in future ammonia emissions model development in other regions.

Publications

  • Mitloehner, F., Swearengen, J., Gooch, C., Ndegwa, P.M., and Jacobson, L. 2010. Chapter 3: Husbandry, Housing, and Biosecurity. IN: Guide for the Care and Use of Agricultural Animals in Research and Teaching, 3rd Edition. Federation of Animal Science Societies. pp. 16-29. ISBN: 9781884706110 (Spiral bound copy available from publisher, and online at: http://www.fass.org/docs/agguide3rd/Ag_Guide_3rd_ed.pdf).
  • Ndegwa, P.M., Vaddella, V.K., Hristov, A.N., and Joo, H.S. 2009. Measuring Concentrations of Ammonia in Ambient Air or Exhaust Air Stream using Acid Traps. J. Environ. Qual. 38:647-653.
  • Hristov, A.N., Vander Pol, M., Angle, M., Zaman, S., Schneider, C., Ndegwa, P., Vaddella, V.K., Johnson, K., Shingfield, K.J., and Karnati, S.K.R. 2009. Effect of lauric acid and coconut oil on ruminal fermentation, digestion, ammonia losses from manure, and milk fatty acid composition in lactating cows. J. Dairy Sci. 92:5561-5582.
  • Hristov, A.N., Zaman, S., Vander Pol, M., Ndegwa, P., Campbell, L, and Silva, S. 2009. Nitrogen Losses from Dairy Manure Estimated Through Nitrogen Mass Balance and Chemical Markers. J. Environ. Qual. 38:2438-2448.


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

Outputs
OUTPUTS: Ammonia Mitigation - We conducted a thorough review of available best management practices or strategies in the mitigation of ammonia emissions in the context of concentrated animal feeding operations (CAFOs). We researched the impact of diet modification to reduce ammonia emissions in livestock facilities. The data so far indicate that low crude protein diets reduced the amounts of nitrogen excreted and therefore, subsequently reduced ammonia loss. In a parallel supporting study, we looked at an improvement of a methodology to evaluate the reduction of ammonia emissions using acid traps. The results revealed that the efficiency of the ammonia traps decreases with the amount of ammonia to be trapped even when the capacity of the acid traps greatly exceeds the estimated stoichiometric capacity of the acid to trap ammonia. Thus, to be able to compare results amongst studies evaluating the effects of similar treatments' effect on ammonia emission from livestock manure, each system needs to be calibrated because each system is unique. Air Quality - We continued monitoring air quality in typical open free-stall dairy operations under the auspices of the National Air Emissions Monitoring Study (NAEMS). The main activities involved data collection and maintenance of the equipment at the project site near Sunnyside, Washington. In another collaborative research project, we researched varieties and quantities of pathogens in the air within livestock facilities. PARTICIPANTS: Washington State University: Pius M. Ndegwa, Assistant Scientist; Hung soo Joo, Post-Doctoral Research Associate; Venkata K. Vaddella, Graduate Student Research Assistant. Pennsylvania State University: Alexander N. Hristov, Associate Professor. Purdue University: Richard, H. Grant, Professor. Purdue Agriculture Air Quality Laboratory: Albert J. Heber, Professor and Executive Director; Jiqin-Qin Ni, Research Assistant Professor; William W. Bogan, Operations Manager; Juan Carlos Ramirez, Post-Doctoral Researcher; Erin Cortus, Post-Doctoral Researcher. TARGET AUDIENCES: Livestock producers, practitioners, consultants, legislators, scientists, and other stakeholders. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Produced a one-stop resource center for strategies of mitigating ammonia emissions from livestock operations (CAFOs). Completed development of a more reliable method for measuring ammonia emissions from ambient air. Completed development of a potential approach for remediation of oil-contaminated soils using biological systems approaches.

Publications

  • Joo, H.-S., Ndegwa, P.M., Shoda, M., and Phae, C.-G. 2008. Bioremediation of oil-contaminated soil using 'Candida catenulata' and food waste. Environmental Pollution. 156(3):891-896.
  • Ndegwa, P.M., Hristov, A.N., Arogo, J., and Sheffield, R.E. 2008. A review of ammonia emissions mitigation techniques for concentrated animal feeding operations. Biosystems Engineering. 100(4):453-469.


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

Outputs
OUTPUTS: Collaborative research continued in the addition of value to animal waste and other low-value agricultural residuals through bioconversion of these materials to biohydrogen. This research work continued to focus on improving production yields using base material (for example glucose). Data so indicate that long chain fatty acids inhibit methanogens and hence improve hydrogen yields in mixed microbial fermentations. In this work, linoleic acid (LA), a long chain fatty acid bearing 18 carbons and two double bonds, inhibited hydrogen consumption in a mixed anaerobic culture acclimated to glucose. A peer review article was published in the past year from this work. Another research collaborative project that was conducted in the year investigated the impact of diet modification on reduction of ammonia emission in livestock facilities. Data at hand so far indicate that low crude protein diets reduced the amounts of nitrogen excreted and therefore, subsequently reduced ammonia loss. One parallel but supporting study that was finished in the past year worked on improved methodology of evaluating the reduction of ammonia emissions in vitro. The results revealed that, the efficiency of the ammonia traps decreases with the amount of ammonia to be trapped even when the capacity of the acid traps highly exceeds the estimated stoichiometric capacity of the acid to trap ammonia. From all the data collected in all experiments on this method, it was concluded that, to be able to compare results amongst studies evaluating similar treatments' effect on ammonia emission from livestock manure, each system needs to be calibrated because each system is unique. A peer review article is in preparation based on this work. Another collaborative research is looking at variety and quantities of pathogens in the air within livestock facilities. We have no results yet on this research project. The other research project that was initiated in the past year is monitoring of air quality in typical open free-stall dairy operations. The methodology has been worked out and the equipment setup is complete. Data collection is on-going and will continue for the next two years. Due to confidentiality issues, we cannot report on most of the data being gathered until the project is over. We can, however, report on the methodologies. With respect to this, we have submitted a methodology paper for an international professional conference meeting in Brazil this year. A peer review paper will soon be prepared. PARTICIPANTS: Ndegwa, P.M.(PI); Wang, L.; Hristov, A.N.; Vaddella, V.K.; Joo, H.S.; Hamilton, D.W.; Lalman, J.A.; Cumbe, H.J.; Seth, R.; Chowdhury, W.; Meschke, S.J. TARGET AUDIENCES: Livestock producers and related stakeholders, researchers, educators, and legislators.

Impacts
1) Improvement in the yields of hydrogen from biomass in a mixed microbial environment may enhance economic viability and thus widespread adoption of this technology. 2) A more accurate method for evaluating in vitro ammonia loss reduction from dietary manipulation will greatly improve and facilitate assessment of this (dietary changes) approach for mitigation of ammonia emission from livestock facilities. 3) Development of methodology for measuring emissions from open free-stall livestock barns will go a long way in encouraging more research projects in this area. In addition, our current project will provide considerable data that EPA can use in making legislative decisions affecting livestock industry. Information will also be useful to producers in selection or implementation of best management practices to reduce such emissions.

Publications

  • Chowdhury, N., Lalman, J.A., Seth, R., and Ndegwa, P. 2007. Biohydrogen Production by Mesophilic Anaerobic Fermentation of Glucose in the Presence of Linoleic Acid. J. Envir. Engrg. 133(12):1145-1152.
  • Ndegwa, P.M., Hamilton, D.W., Lalman, J.A., and Cumba, H.J. 2008. Effects of cycle-frequency and temperature on the performance of anaerobic sequencing batch reactors (ASBRs) treating swine waste. Bioresource Technology. 99(6):1972-1980.
  • Ndegwa, P.M., Wang, L., and Vaddella, V.K. 2007. Potential strategies for process control and monitoring of stabilization of dairy wastewaters in batch aerobic treatment systems. Process Biochemistry. 42(9):1272-1278.
  • Ndegwa, P.M., Wang, L., and Vaddella, V.K. 2007. Stabilization of dairy wastewater using limited-aeration treatments in batch reactors. Biosystems Engineering. 97(3):379-385.


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

Outputs
Research is on-going in the addition of value to animal waste and other low-value agricultural residuals through bioconversion of these materials in hydrogen. Preliminary work has focused more on improving production yields using base material (for example glucose). Preliminary data indicate that long chain fatty acids can inhibit methanogens and hence improve hydrogen yields in mixed microbial fermentations. Additional on-going research is on the investigation of novel nitrogen mass balance for estimation of nitrogen loss from animal feeding operations. The study was conducted in an 8-lactating Holstein cow-pen in a free-stall facility with daily scraping system for manure removal. Feed delivered and milk yields were recorded daily. The amount of manure removed from the pen was recorded daily and samples were collected for analyses, 24 hr. after excretion. Grab fecal and spot urine samples were collected weekly from each cow and analyzed for composition. Output of urine and feces was estimated using acid-insoluble ash and creatinine as markers. Feces, urine, and manure samples were analyzed for N, N-15, P, Cu, and Ca. Under the conditions (15.6 degrees-C; 2.3m/s wind speed; and 72.6 percent RH) in which this study was conducted, N losses from manure were high in the first 24 hr. after excretion. Data also suggest that ratios of N to non-volatile elements and N-15 analyses are useful in estimating N losses from dairy manure. Further active research is on the stabilization of animal manure through limited-aeration treatments. Research was conducted to study treatment of dairy wastewater using limited-aeration treatments. Results showed that during the first 3-4 days of limited-aeration treatments at 0.034 and 0.067 L[air]/L[manure]/min, dissolved oxygen (DO) remained close to the detection limit but, based on ORP levels (-30 to 100 mV), the wastewater oxidation-reduction status remained anoxic; the environment remained aerobic after this phase. The 70% maximum removal of both COD and TVS observed by day 8 of treatment at either aeration rate indicated that the two-fold decrease in the aeration rate did not alter the ultimate reduction of the organic strength. The kinetic-studies established bio-stabilization constants of 0.168 and 0.144 day/day at the aeration rates of 0.067 and 0.034 L[air]/L[manure]/min, respectively. Research was also conducted to study the relationships between pH, dissolved oxygen (DO), and oxidation-reduction potential (ORP) during limited aeration of dairy wastewaters and to determine suitable method(s) for monitoring and control of this treatment process. The results of this study ascertained that, close to the detection limit of commercially available DO probes, DO is a poor indicator of the oxidation-reduction status of the dairy wastewater during this treatment processes. All three parameters (ORP, DO, and pH) displayed features defining stabilization of the wastewater and hence all three can be used singly or in combination to monitor and/or to control this treatment process.

Impacts
Provision of simpler and practical ammonia loss from animal facilities determination methods to facilitate development of appropriate interventions points, and control measures. A more convenient and accurate method for control and monitoring of aerobic stabilization processes of dairy wastewaters in concentrated animal feeding operations is available to researchers and producers. An alternative and cost-effective process of stabilization of dairy wastewater using limited aeration treatment is available for producers.

Publications

  • Hamilton, D.W., Kourtchev, I.N., Ndegwa, P.M., Cumba, H.J., and Gioelli, F. 2006. Methane and carbon dioxide emissions from simulated anaerobic swine manure treatment lagoons under summer conditions. Trans. of the ASABE. 49(1):157-165.
  • Templer, J., Lalman, J.A. , Jing, N., and Ndegwa, P.M. 2006. Influence of C18 long chain fatty acids on hydrogen metabolism. Biotechnology Progress. 22(1):199-207.
  • Zhu, J., Luo, A. , and Ndegwa, P.M. 2006. Effect of microbial additives combined with aeration on reduction of nutrients in swine manure. Applied Engineering in Agriculture. 49(1):203-208.