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Biological Systems Engineering Ndegwa Research Site

Publications

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Refereed Journal Articles   |   Conference Papers & Presentations   |   Abstracts   |   Extension Publications

Refereed Journals Articles

  • S.S. Coulibaly, M. Apasiku, P.M. Ndegwa, I. A. Bi Zoro. 2019. Growth, reproduction, and life cycle of Eudrilus eugeniae in cocoa and cashew residues. Applied Soil Ecology 143, 153-160.
  • Zeb, I., J. Ma, Q. Zhao, F. Mehboob, G.K. Kafle, A. Yaqub, R. Nazir, P.M. Ndegwa, C. Frear. 2019. Kinetic and microbial analysis of methane production from dairy wastewater anaerobic digester under ammonia and salinity stresses. J. Cleaner Production 219(10): 797-808.
  • Woodbury, B.L., R.A. Eigenberg, H.G. Minns, P.M. Ndegwa. 2018. Data Analysis Protocol for Using Resistivity Array as an Early-Warning Wastewater Pond Leak Detector. Journal of Environmental and Engineering Geophysics 23(2), 251-260.
  • Kafle, G.K, H.S. Joo, P.M. Ndegwa. 2018. Sampling duration and frequency for determining emission rates for naturally ventilated dairy barns. Trans. of ASABE 61(2), 681-691.
  • Zeb, I., J. Ma, C. Frear, Q. Zhao, P. Ndegwa, Y. Yao, G.K. Kafle. 2017. Recycling separated liquid-effluent to dilute feedstock in anaerobic digestion of dairy manure. Energy 119, 1144-1151.
  • Neerackal, G.M., P.M. Ndegwa, H. S. Joo, J. H. Harrison. 2017. Manure-pH management for mitigating ammonia emissions from dairy barns and liquid manure storages. Applied Engineering in Agriculture 33(2), 235-242.
  • Wenlong, C., V. Vaddella, S. Biswas, K. Perkins, C. Clay, T. Wu, Y. Zheng, P. Ndegwa, P. Pandey. 2016. Assessing the changes in E. coli levels and nutrient dynamics during vermicomposting of food waste under lab and field scale conditions. Environ. Sci. Pollut. Res. Int. 23(22):23195-23202.
  • Khalil, T.M., S.S. Higgins, P.M. Ndegwa, C.S. Frear, C.O. Stöckle. 2016. Assessing the effect of different treatments on decomposition rate of dairy manure. Journal of Environmental Management. 182:230-237.
  • Wang, X., P.M. Ndegwa, H.S. Joo, G.M. Neerackal, C.O. Stöckle, H. Liu, J.H. Harrison. 2016. Indirect method versus direct method for measuring ventilation rates in naturally ventilated dairy houses. Biosystems Engineering 144: 13-25.
  • Neerackal, G.M., P.M. Ndegwa, H.S. Joo, X. Wang, C.S. Frear, J.H. Harrison, M.W. Beutel. 2016. Potential application of Alcaligenes faecalis strain No. 4 in mitigating ammonia emissions from dairy wastewater. Bioresource Technology 206: 36-42.
  • Wang, X., P.M. Ndegwa, H.S. Joo, G.M. Neerackal, J.H. Harrison, C.O. Stöckle, H. Liu. 2016. Reliable Low-cost devices for monitoring ammonia concentrations and emissions in naturally ventilated dairy barns. Environmental Pollution 208(B): 571-579.
  • Chen, Y., J.H. Harrison, P. Ndegwa, D. Wilks, L. VanWieringen, W. Chalupa, F. Sun. 2016. Case Study: Effect of strategic ration balancing on the efficiency of milk protein production and environmental impact of dairy cows in a commercial herd. The Professional Animal Scientist 32(1): 115-133.
  • Joo, H.S., P.M. Ndegwa, X. Wang, A.J. Heber, J.-Q. Ni, E.L. Cortus, J.C. Ramirez-Dorronsoro, B.W. Bogan, L. Chai. 2015. Ammonia and hydrogen sulfide concentrations and emissions for naturally-ventilated freestall dairy barns. Trans. ASABE 58(5): 1321-131.
  • Neerackal, G.M., P.M. Ndegwa, H.S. Joo, X. Wang, J.H. Harrison, A.J. Heber, J.-Q. Ni, C. Frear. 2015. Effects of anaerobic digestion and solids separation on ammonia emissions from stored and land applied dairy manure. Water, Air, & Soil Pollution 226(9):301.
  • Joo, H.S., K. Park, K. Lee, P. Ndegwa. 2015. Mass concentration coupled with mass loading rate for evaluating PM2.5 pollution status in the atmosphere: a case study based on dairy barns. Environmental Pollution 207: 374-380.
  • Page, L.H., J.-Q. Ni, H. Zhang, A.J. Heber, N.S. Mosier, X. Liu, H.-S. Joo, P.M. Ndegwa, J.H. Harrison. 2015. Reduction of volatile fatty acids and odor offensiveness by anaerobic digestion and solid separation of dairy manure during manure storage. J. Environmental Management. 152, 91-98.
  • Joo, H.S., P.M. Ndegwa, A.J. Heber, B.W. Bogan, J.-Q. Ni, E.L. Cortus, J.C., Ramirez-Dorronsoro. 2015. Greenhouse gas emissions from naturally ventilated freestall dairy barns. Atmospheric Environment 102: 384–392.
  • 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 225(9).
  • 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.
  • 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(4): 1923.
  • Joo, H.S., P.M. Ndegwa, A.J. Heber, J.-Q. Ni, B.W. Bogan, E.L. Cortus, J.C. Ramirez-Dorronsoro. 2014. A direct method of measuring gaseous emissions from naturally ventilated dairy barns. Atmospheric Environment. 86: 176-186 (PDF Full Text).
  • 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 (PDF Full Text).
  • 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 (PDF Full Text).
  • 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 (PDF Full Text).
  • 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 (PDF Full Text).
  • Liaw, S.S., Z. Wang, P. Ndegwa, C. Frear, S. Ha, C.Z. Li, M. Garcia-Perez. 2012. Effect of Temperature on the Yield and properties of Bio-oils Obtained from the Auger Pyrolysis of Douglas Fir Wood. Analytical and Applied Pyrolysis 93:52-62.
  • Vaddella, V.K., P.M. Ndegwa, H.S. Joo. 2011. Ammonia loss from simulated post-collection storage of scraped and flushed dairy-cattle manure. Biosystems Engineering 110:291-296 (PDF Full Text).
  • Pandey, P.K., P.M. Ndegwa, R. Alldredge, M. Pitts. 2011. Efficacies of inocula on the startup of anaerobic reactors treating dairy manure under stirred and unstirred conditions. Biomass and Bioenergy 35:2705-2720 (PDF Full Text).
  • Vaddella, V.K., P.M. Ndegwa, A. Jiang. 2011. An Empirical model for ammonium ion dissociation in liquid dairy manure. Trans. of the ASABE 54(3):1119-1126 (PDF Full Text).
  • Hristov, A.N., M. Hanigan, A. Cole, R. Todd, T. McAllister, P.M. Ndegwa, A. Rotz. 2011. Ammonia emissions from dairy farms and beef feedlots: A review. Can. J. Anim. Sci. 91:1-35 (PDF Full Text).
  • Vaddella, V.K., P.M. Ndegwa, H. Joo, and J.L. Ullman. 2010. Impact of Separating Dairy Cattle Excretions on Ammonia Emissions. J. Environ. Qual. 39:1807-1812 (PDF Full Text).
  • Angle, M., A.N. Hristov, A.N., S. Zaman, C. Schneider, P. M. Ndegwa, V.K. Vaddella. 2010. Effect of dietary concentrate on rumen fermentation, digestibility, and nitrogen in dairy cows. J. Dairy Sci. 93:4211-4222 (PDF Full Text).
  • Pandey, P.K., P.M. Ndegwa, R. Alldredge, M. Pitts. 2010. Modeling effects of granules on the start-up of anaerobic digestion of dairy wastewater with Langmuir and Extended Freundlich Equations. Bioprocess and Biosyst Engineering 33:833-845 (PDF Full Text).
  • Angle, M., A.N. Hristov, A.N., S. Zaman, C. Schneider, P. M. Ndegwa, V.K. Vaddella. 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 (PDF Full Text) .
  • Hristov, A.N., S. Zaman, M. Vander Pol, P. Ndegwa, L. Campbell, S. Silva. 2009. Nitrogen Losses from Dairy Manure Estimated Through Nitrogen Mass Balance and Chemical Markers. J. Environ. Qual. 38:2438-2448 (PDF Full Text).
  • Ndegwa, P.M., V. Vaddella, A.N. Hristov, H.S. Joo. 2009. Measuring concentrations of ammonia in ambient air or exhaust air stream using acid traps. J. Environmental Quality 38:647-653 (PDF Full Text).
  • Joo, H.S., P.M. Ndegwa, M. Shoda, C. Phae. 2008. Bioremediation of oil-contaminated soil using Candida catenulata and foodwaste. Environmental Pollution 156(3):891-896 (PDF Full Text).
  • Ndegwa, P.M., A.N. Hristov, J. Arogo, R.E. Sheffield. 2008. A review of ammonia emissions mitigation techniques for concentrated animal feeding operations. Biosyst. Engineering 100(4):453-469 (PDF Full Text).
  • Ndegwa, P.M., D.W. Hamilton, J.A. Lalman, H.J. Cumba. 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 (PDF Full Text).
  • Chowdhury, N., J. A. Lalman, R. Seth, P.M. Ndegwa. 2007. Biohydrogen production by mesophilic anaerobic of glucose in the presence of linoleic acid. Environmental Engineering-ASCE 133(12):1145-1152 .
  • Ndegwa, P.M., L. Wang, V.K. Vaddella. 2007. Potential strategies for process control and monitoring of stabilization of dairy wastewaters in batch aerobic treatments systems. Process Biochemistry 42(9): 1272-1278 (PDF Full Text).
  • Ndegwa, P.M., L. Wang, V.K. Vaddella. 2007. Stabilization of dairy wastewater using limited-aeration treatments in batch reactors. Biosystems Engineering 97(3):379-385 (PDF Full Text).
  • Templer J, J.A. Lalman, N. Jing, P.M. Ndegwa. 2006. Influence of C18 long chain fatty acids on hydrogen metabolism. Biotechnology Progress 22(1):199-207 (PDF Full Text).
  • Zhu, J., A. Luo, P.M. Ndegwa. 2006. Effect of microbial additives combined with aeration on reduction of nutrients in swine manure. Trans. of the ASABE 49(1):203-280 (PDF Full Text).
  • Hamilton, D.W., I.N. Kourtchev, P.M. Ndegwa, H.J. Cumba. 2006. Methane and carbon dioxide emissions from simulated anaerobic swine manure treatment lagoons under summer conditions. Trans. of the ASABE 49(1):157-165 (PDF Full Text).
  • Ndegwa, P.M., D.W. Hamilton, J.A. Lalman, H.J. Cumba. 2005. Optimization of Anaerobic Sequencing Batch Reactors (ASBRs) Treating Dilute Swine Slurries.Trans. of the ASAE 48(4):1575-1583 (PDF Full Text) .
  • Zhu J., Luo, A., Zhou, Y., Ndegwa, P.M., Schmidt, D.R. 2004. The Age Effect of Dairy Feedlots on Manure Nutrient Seepage in Loam Soils. Biosystems Eng. 89(2):223-229 (PDF Full Text).
  • Ndegwa, P.M., 2004. Solids Separation Enhances Reduction of Organic Strength of Swine Manure Subjected to Aeration Treatments. Trans. of the ASAE 47(5):1659-1666 (PDF Full Text).
  • Zhu, J., A. Luo, Y. Zhou, Ndegwa, P.M., D. Schmidt. 2004. Nutrient Seepage from Operating Turkey Buildings with a Litter System. Water, Air, and Soil Pollution 155(1-4):87-101 (PDF Full Text).
  • Ndegwa, P.M. 2004. Limitations of Orthophosphates Removal during Anaerobic Batch Treatment of Piggery Slurry. Biosystems Engineering 87(2):201-208 (PDF Full Text).
  • Zhu, J., Ndegwa, P.M., Z. Zhang. 2004. Manure Sampling Procedures and Nutrient Estimation by the Hydrometer Method for Gestation Pigs. Bioresource Technology 92(3):243-250 (PDF Full Text).
  • Ndegwa, P.M., J. Zhu, A. Luo. 2003. Effects of Bioreactor Temperature and Time on Odor-Related Parameters in Aerated Swine Manure Slurries. J. Environ. Technology 24(8):1007-1016 (PDF Full Text) .
  • Ndegwa, P.M., J. Zhu, A. Luo, D.W. Hamilton. 2003. Enhanced Phosphorus Removal from Swine Manure in Aerated Batch Reactors. Trans. of the ASAE 46(3): 797-803 (PDF Full Text).
  • Zhu, J., Ndegwa, P.M., A. Luo. 2003. Temperature Effects on Pig Manure under Low-Level Batch Aeration. The International Journal of Environ. Studies 60(5): 523-533.
  • Ndegwa, P.M., J. Zhu. 2003. Sampling Procedures for Piggery Slurry in Deep Pits for Estimation of Nutrient Content. Biosystems Engineering 85(2):239-248 (PDF Full Text).
  • Ndegwa, P.M. 2003. Solids Separation Coupled With Batch-Aeration Treatment For Odor Control From Liquid Swine Manure. J. Environ. Sci. Health B38(5): 631-643 (PDF Full Text).
  • Zhu, J., Z. Zhang, Ndegwa, P.M. 2003. Using a Soil Hydrometer to Measure the Nitrogen and Phosphorus Contents in Pig Slurries. Biosystems Engineering 85(1):121-128 (PDF Full Text).
  • Ndegwa, P.M., J. Zhu, A. Luo. 2003. Discussions and Closure to “Effects of Solids Levels and Chemical Additives on Removal of Solids and Phosphorus in Swine Manure”. J. Environ. Eng.-ASCE 129(5):485-487 (PDF Full Text).
  • Zhu, J., Ndegwa, P.M., Z. Zhang. 2003. Settling Characteristics of Nursery Pig Manure and Nutrient Estimation by the Hydrometer Method. J. Environ. Sci. Health B38(3):379-390 (PDF Full Text).
  • Zhu, J., A. Luo, Y. Zhou, Ndegwa, P.M., D. Schmidt. 2002. Barn Age Impact on Nutrient Leaching from Turkey Barns Built on Clay Loam Soils. Trans. of the ASAE 45(6):1971-1976 (PDF Full Text).
  • Ndegwa, P.M., J. Zhu, A. Luo. 2002. Influence of temperature and time on phosphorus removal in swine manure during batch aeration. J. Environ. Sci. Health B38(1):73-87 (PDF Full Text).
  • Luo, A., J. Zhu, Ndegwa, P.M. 2002. Influence of anaerobic pre-conditioning on phosphorus removal in swine manure by aeration. J. Water, Air, and Soil Pollution 140(1-4):219-230 (PDF Full Text).
  • Ndegwa, P.M., J. Zhu, A. Luo. 2002. Stratification of Solids, Nitrogen and Phosphorus in Swine Manure in Deep Pits Under Slatted Floors. Bioresour. Techno. 83(3):203-211 (PDF Full Text).
  • Zhu, J., Ndegwa, P.M., A. Luo. 2002. Bacterial Responses to Temperature during Aeration of Pig Slurry. J. Environ. Sci. Health B37(3):265 – 275 (PDF Full Text).
  • Luo, A., J. Zhu, Ndegwa, P.M. 2002. Removal of Carbon, Nitrogen, and Phosphorus in Pig Manure by Continuous and Intermittent Aeration at Low Redox Potentials. Biosystems Eng. 82(2):209-215 (PDF Full Text).
  • Ndegwa, P.M., J. Zhu, A. Luo. 2002. Effects of Solids Separation and Time on the Production of Odorous Compounds in Stored Pig Slurry. Biosyst. Engineering 81(1): 127-133 (PDF Full Text).
  • Thompson, S.A, Ndegwa, P.M., W.C. Merka, A. B. Webster. 2001. Reduction in Manure Weight and Volume Using an In-House Layer Manure Composting System under Field Conditions. Applied Poultry Research 10(3):255-261 (PDF Full Text).
  • Zhu, J., Ndegwa, P.M., A. Luo. 2001. Effect of solid-liquid separation on BOD and VFAs in swine manure. J. Environmental Technology 22(10): 1237-1243 (PDF Full Text).
  • Ndegwa, P.M., J. Zhu, A. Luo. 2001. Effect of Batch Aeration-Treatment on the Solubility of Phosphorus in Pig Manure. J. Agricultural Engineering Res. 80(4): 365-371 (PDF Full Text).
  • Zhu, J., A. Luo, Ndegwa, P.M. 2001. Raising pH by Low Level Aeration for Soluble Phosphorus Removal from Swine Manure. Trans. of the ASAE 44:391-396 (PDF Full Text).
  • Ndegwa, P.M., J. Zhu, A. Luo. 2001. Effects of Solids Levels and Chemical Additives on Removal of Solids and Phosphorus in Swine Manure. J. Environmental Engineering-ASCE 127(12):1111-1115 (PDF Full Text) .
  • Luo, A., J. Zhu, Ndegwa, P.M. 2001. Phosphorus Transformations in Swine Manure during continuous and intermittent Aeration Processes. Trans. of the ASAE 44(4):967-972 (PDF Full Text).
  • Ndegwa, P.M., S.A.Thompson. 2001. Integrating Composting and Vermicomposting in the Treatment and Bioconversion of Biosolids. Bioresource Techno. 76(2):107-112 (PDF Full Text).
  • Zhu, J., A. Luo, Ndegwa, P.M. 2001. The Effect of Limited Aeration on Swine Manure Phosphorus Removal. J. Environ. Sci. Health B36(2):209-218 (PDF Full Text).
  • Ndegwa, P.M., S.A.Thompson. 2000. Effects of C-to-N Ratio on Vermicomposting of Biosolids. Bioresource Technology 75(1):7-12 (PDF Full Text).
  • Zhu, J., Ndegwa, P.M., A. Luo. 2000. Changes in Swine Manure Solid Components During Storage Relating to Separation Efficiency. Applied Engineering in Agriculture 16(5): 571-575 (PDF Full Text).
  • Ndegwa, P.M., S. A. Thompson, W. C. Merka. 2000. A Dynamic Simulation Model of in-situ Composting of Caged-Layers’ Manure. Compost Sci. & Utilization 8(3):190-202 (PDF Full Text).
  • Ndegwa, P.M., S.A.Thompson, K.C. Das. 1999. Effects of Stocking Density and Feeding Level on Vermicomposting of Biosolids. Bioresource Technology 71(1): 5-12 (PDF Full Text).
  • Ndegwa, P.M., S. A. Thompson, W. C. Merka. 1991. Fractionation of Poultry Litter for Enhanced Utilization. Trans. of the ASAE 34(3):992-997 (PDF Full Text).

Quick Links:
Refereed Journal Articles   |   Conference Papers & Presentations   |   Abstracts   |   Extension Publications

Conference Papers & Presentations

  • Coulibary, S.S. Y. Yao, P.M. Ndegwa. 2019. Coupling anaerobic digestion and vermicomposting to extract bioenergy and nutrients from food- and yard-waste. Presented at ASABE Annual Intl Conference. Submission #1 1901640; Boston, Massachusetts, July 07 – 10.
  • Zeb, I., G.K. Kafle, X. Xue, P.M. Ndegwa. 2019 Enhanced biogas yield in anaerobic sequencing batch reactors using a cationic polymer. Presented at ASABE Annual Intl Conference. Submission # 1901822; Boston, Massachusetts, July 07 – 10.
  • Alege, F.P, L.E. DeVetter, H. Tao, P.M. Ndegwa. 2019 Enhanced biogas yield in anaerobic sequencing batch reactors using a cationic polymer. Presented at ASABE Annual Intl Conference. Submission # 1900907; Boston, Massachusetts, July 07 – 10.
  • Kafle, G., L. Khot, P. Ndegwa, I. Zeb. 2018. Identification of potential near infrared spectral bands for rapid sensing of dairy manure nutrients. Presented at ASABE Annual Intl Conference. Paper #1700422; Spokane, Washington, July 15 – 19.
  • Kafle, G., H. Joo, P. Ndegwa. 2018. Sampling duration and frequency to obtain credible emission factors for naturally ventilated dairy barns. Presented at ASABE Annual Intl Conference. Paper #1701197; Spokane, Washington, July 15 – 19.
  • Xue, X., G. Kafle, P. Ndegwa. 2018. Balancing C/N ratio for mitigating ammonia emissions from dairy manure with A. faecalis strain No. 4. Presented at ASABE Annual Intl Conference. Paper #1701206; Spokane, Washington, July 15 – 19.
  • Kafle, G., L. Khot, P. Ndegwa. 2016. Evaluation of near infrared spectroscopy for rapid sensing of dairy manure nutrients. Presented at ASABE Annual Intl Conference. Orlando, Florida, July 17 – 20.
  • Zeb, I., J. Ma, C. Frear, P. Ndegwa. 2016. Separated-effluent recycling in the anaerobic digestion process: effects of ammonia and salinity. Presented at ASABE Annual Intl Conference. Orlando, Florida, July 17 – 20.
  • Zeb, I., G.K. Kafle, X. Xue, P.M. Ndegwa. 2016. Modelling ammonia inhibition for anaerobic digestion of dairy manure with acclimated and un-acclimated seed. Presented at ASABE Annual Intl Conference. Orlando, Florida, July 17 – 20.
  • Wang, X., H.S. Joo, G.M. Neerackal, P.M. Ndegwa. 2015. Direct versus indirect methods for ventilation rates measurement in naturally ventilated livestock buildings. ASABE Annual International Conference. Paper number 152188289; New Orleans, Louisiana, July 26 – July 29.
  • Wang, X., H.S. Joo, G.M. Neerackal, P.M. Ndegwa, L. Yu, Y. Ma, H. Liu. 2015. A Simplified Direct Method for Determining Ventilation Rates in Naturally Ventilated Dairy Barns. ASABE Annual International Conference. Paper number 125188315; New Orleans, Louisiana, July 26 – July 29.
  • Wang, X., H.S. Joo, G.M. Neerackal, P.M. Ndegwa, J.H. Harrison. 2015. Passive Samplers for Monitoring Ammonia Emissions in Naturally Ventilated Dairy Barns. ASABE Annual International Conference. Paper number 125188318; New Orleans, Louisiana, July 26 – July 29.
  • G.M. Neerackal, H.S. Joo, X. Wang, P.M. Ndegwa. 2015. Enhanced Biological Treatment for Mitigating Ammonia and Odor Emissions from Dairy Wastewaters. ASABE Annual International Conference. Paper number 152186218; New Orleans, Louisiana, July 26 – July 29.
  • 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. ASABE and CSBE/SCGAB Annual International Conference. Paper number 1895745; Montreal, Quebec, Canada, July 13 – 17.
  • Neerackal, G.M., H.S. Joo, P.M. Ndegwa, J.H. Harrison. 2014. Manure-pH management for mitigating ammonia emissions from manure-flush dairy barns. ASABE and CSBE/SCGAB Annual International Meeting. Paper number 1892636; Montreal, Quebec, Canada, July 13-17.
  • 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.
  • 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.
  • 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.
  • 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.
  • Koirala K., H. Joo, P. Ndegwa, C. Frear, C. Stockle, J. Harrison. 2013. Influence of Anaerobic Digestion of Dairy Manure on Ammonia Volatilization Mechanism. Paper number 131593184, ASABE Annual international Conference; July 21-24; Kansas City, Missouri.
  • 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.
  • Joo, H.J., P.M. Ndegwa, J. Harrison, E.Whitefield, A.J. Heber,J.Q. Ni. Emissions of ammonia and greenhouse gases (GHG) from anaerobically digested and undigested dairy manure systems. Paper number 1337962, ASABE Annual International Conference; Dallas, TX, Jul 29 – Aug 1.
  • Joo, H.S., P.M. Ndegwa, A.J. Heber, J.Q. Ni, W.W. Bogan, J.C. Ramirez-Dorronsoro, E. Cortus. 2012. Emissions of Greenhouse Gases from Naturally Ventilated Free-Stall Dairy Barns. Paper number 1337965, ASABE Annual International Conference; Dallas, TX, Jul 29 – Aug 1.
  • 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. Paper number 1337963, ASABE Annual International Conference; Dallas, TX, Jul 29 – Aug 1.
  • 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. Paper number 1110972, ASABE Annual International Conference; Dallas, TX, Jul 29 – Aug 1.
  • Hamilton, D.W., M.T. Steele, P.M. Ndegwa. 2012. The anaerobic sequencing batch reactor (ASBR), an advanced anaerobic digester for dilute live swine production byproducts. Third CIGR International Conference of Agricultural Engineering (CIGR-AgEng2012), Valencia, Spain, July 8-12.
  • Vaddella, V.K., P.M. Ndegwa, A. Jiang. 2011. A Model for Overall Mass Transfer Coefficient of Ammonia from Dilute Dairy Manure Slurries. Paper number 1110972, ASABE Annual International Meeting. Lousiville, KY, August 7-10.
  • Joo, H.S., P.M. Ndegwa, A.J. Heber, J.-Q. Ni, J.C. Ramirez-Dorronsoro, E.L. Cortus. 2011. Association’s Annual Conf. & Exhibition, to be held in Detroit, MI, June 16-19, 2009. Particulate matter emissions from naturally ventilated free-stall dairy barns. Air & Waste Management Association’s Annual Conf. & Exhibition. Orlando, FL, June 20-24.
  • V.K. Vaddella, P.M. Ndegwa, H.S. Joo. 2010. A Process-based Model for Ammonia Emissions from Storages of Flushed Dairy Manure. ASABE Intl. Symposium on Air Quality and Manure Management. Dallas, TX, September 13-15.
  • V.K. Vaddella, P.M. Ndegwa, H.S. Joo. 2010. A Model for Ammonia Dissociation Constant in Dairy Manure. ASABE Intl. Symposium on Air Quality and Manure Management. Dallas, TX, September 13-15.
  • V.K. Vaddella, P.M. Ndegwa, H.S. Joo. 2010. A Process-based Model for Ammonia Emissions from Storages of Flushed Dairy Manure. ASABE Annual International Meeting. Pittsburg, PA, June 20-23.
  • Ndegwa, P.M., V.K. Vaddella, A.N. Hristov, H.S. Joo. 2009. Revisiting the method for measuring ammonia concentrations in ambient air or exhaust air stream using acid traps. Air & Waste Management Association’s Annual Conf. & Exhibition, to be held in Detroit, MI, June 16-19, 2009.
  • Ndegwa, P.M., H.S. Joo, A.J. Heber, J.C. Ramirez-Dorronsoro, E.L. Cortus, J.-Q. Ni, W.W. Bogan. A Method for determining gaseous emissions from naturally ventilated freestall dairy barns. Air & Waste Magt Association’s Annual Conf. & Exhibition, to be held in Detroit, MI, June 16-19, 2009.
  • V.K. Vaddella, P.M. Ndegwa, H.S. Joo. 2009. Simulation of ammonia emissions from scraped and flushed dairy manure Post-Collection Storages. ASABE Annual International Meeting.Reno, Nevada, June 21-24.
  • V.K. Vaddella, P.M. Ndegwa. 2009. Ammonia Emissions from Manure Storages using urine-feces separation systems. ASABE Annual International Meeting. Reno, Nevada, June 21-24.
  • V.K. Vaddella, P.M. Ndegwa. 2009. Modeling of convective mass transfer coefficient and dissociation constant for ammonia in dairy wastewater. ASABE Annual International Meeting. Reno, Nevada, June 21-24.
  • Hamilton, D.W., M.E. Murie, A.M.A Khan, P.M Ndegwa. 2008. Vermicomposting of Poultry Litter: Process Optimization. ASABE Paper No: 084896. ASABE International Meeting, Rhode Island Convention Center, Providence, Rhode Island.
  • Ndegwa, P.M., A.N. Hristov, J. Arogo, R.E. Sheffield. 2008. Ammonia emissions mitigation techniques for concentrated animal feeding operations. Mitigation Air Emissions from Animal Feeding Operations: Exploring the advantages, Limitations, and Economics of mitigation technologies. May 19-21, Des Moines, Iowa.
  • Heber, A.J., B.W. Bogan, J.-Q. Ni, T.T. Lim, J.C. Ramirez-Dorronsoro, E.L. Cortus, C. A. Diehl, S.M. Hanni, C. Xiao, K.D. Casey, C.A. Gooch, L.D. Jacobson, J. A. Koziel, F.M. Mitloehner, P. M. Ndegwa, W. P. Robarge, L. Wang, R. Zhang. 2008. The National Air Emissions Monitoring Study: Overview of Barn Sources. The 8th International Livestock Symposium (ILES VIII), Iguassu Falls, Brazil, Aug. 31-Sept. 4.
  • Ndegwa, P.M., H.S. Joo, A.J. Heber, J.C. Ramirez-Dorronsoro, E.L. Cortus, J.-Q. Ni, W.W. Bogan. 2008. A method for Determination of Pollutant Emissions from Naturally Ventilated Freestall Dairy Barns. The 8th International Livestock Symp. (ILES VIII), Iguassu Falls, Brazil, Aug. 31-Sept. 4.
  • A.N. Hristov, S. Zaman, M. Vander Pol, P. Ndegwa, S. Silva, and C.  Kendall. Nitrogen losses from dairy manure estimated through nitrogen mass balance or using markers. 2007 Joint Meeting of ADSA, PSA, AMPA, ASAS. San Antonio, Texas.
  • Ndegwa, P.M., D.W. Hamilton, J.A. Lalman, H.J. Cumba. 2005. Treatment of low strength swine waste using anaerobic sequencing batch reactors (ASBRs). ASAE Paper No. 054081. ASAE International Meeting, Tampa, Florida, USA.
  • Hamilton, D.W., S.D. Carter, P.M. Ndegwa, H.J. Cumba. 2005. Emission of nitrogenous gases from simulated swine manure stabilization ponds. ASAE Paper No. 054030. ASAE International Meeting, Tampa, Florida, USA.
  • Zhu, J., Z. Zhang, P. M. Ndegwa. 2003. Evaluation of the hydrometer method to determine swine manure nutrient content. Presented and published in proceedings of the 9th International Symposium on Animal, Agric. and Food Processing Wastes. Oct. 12-15, 2003, Durham, NC.
  • Ndegwa, P.M., J. Zhu. 2003. Novel procedures for accurate sampling of swine manures. Presented and published in proceedings of the 9th International Symposium on Animal, Agricultural and Food Processing Wastes. October 12-15, 2003, Durham, NC.
  • Hamilton, D.W, I.N. Kourtchev, P.M. Ndegwa, H.J. Cumba, F. Gioelli. 2003. Simulation of anaerobic/facultative lagoon performance using a 1,000-liter pilot facility. ASAE Paper No. 034155. ASAE International Meeting, Las Vegas, Nevada, USA.
  • Ndegwa, P.M., 2003.  Limitations of orthophosphates removal from swine manure during batch-aeration treatments. ASAE Paper No. 034153. ASAE International Meeting, Las Vegas, Nevada, USA.
  • Ndegwa, P.M., J. Zhu, A. Luo. 2002.  Enhanced phosphorus removal in swine manure using aerated batch-reactors. ASAE Paper No. 024097. ASAE-CIGR Congress Annual International Meeting, Chicago, Illinois, USA.
  • Ndegwa, P.M., J. Zhu, A. Luo. 2001.  Temperature effects on phosphorus removal in swine manure under aeration treatment.ASAE Paper No. 012276. ASAE International Meeting, Sacramento, California, USA.
  • Ndegwa, P.M., J. Zhu, A. Luo. 2000.  Improved handling of swine manure via chemically enhanced natural sedimentation. ASAE Paper No. 004140. ASAE Intern. Meeting, Milwaukee, WI.
  • Ndegwa, P.M., J. Zhu, A. Luo. 2000. Solids-liquid separation of swine manure for odor control. ASAE Paper No. 004076. ASAE International Meeting, Milwaukee, Wisconsin.
  • Luo, A., J. Zhu, P.M. Ndegwa.  2000. Fluctuations of phosphorus in swine manure during anaerobic and aerobic processes.  ASAE Paper No. 004122.  ASAE International Meeting, Milwaukee, Wisconsin.
  • Luo, A., J. Zhu, P.M. Ndegwa. 2000. Isolation of bacteria able to utilize odorous compounds as sole carbon and energy source from swine manure.  ASAE Paper No. 008003. ASAE International Meeting, Milwaukee, Wisconsin.
  • Ndegwa, P.M, S.A. Thompson, W.C. Merka. 1999. A Dynamic simulation model of in-situ composting of caged layers’ manure.  Presented at Southern Poultry Science Society Conference on Avian Diseases, January 18-19, 1999 (Abstract S7).
  • Ndegwa, P.M., S.A.Thompson, K.C. Das. 1998. Effects of stocking density and feeding level on vermicomposting of biosolids. Proceedings of Composting in the Southeastern Conference and Expo.  Athens, GA, September 9-11.
  •  Thompson, S.A, W.C. Merka, P.M. Ndegwa. 1997. In-house deep-litter manure management system. ASAE Paper No.974070.  ASAE International Meeting, Minneapolis, MN.
  • Thompson, S.A., W.C. Merka, P.M. Ndegwa. 1991. Fractionation of poultry litter for enhanced utilization. Presented at Conference on Environmentally Sound Agric. Orlando, FL, 16‑18 April.

Abstracts

  • Heber, A.J., B.W. Bogan, J.-Q. Ni, T.T. Lim, J.C. Ramirez-Dorronsoro, E.L. Cortus, C. A. Diehl, S.M. Hanni, C. Xiao, K.D. Casey, C.A. Gooch, L.D. Jacobson, J. A. Koziel, F.M. Mitloehner, P. M. Ndegwa, W. P. Robarge, L. Wang, R. Zhang. 2008. Methods of Monitoring Barn Emissions in the National Air Emissions Monitoring Study. Air & Waste Management Association (A&WMA), Extended Abstract # 118. One Gateway Center, Third Floor, 420 Fort Duquesne Blvd., Pittsburgh, PA 15222-1435.
  • A.N. Hristov, S. Zaman, M. Vander Pol, P. Ndegwa, S. Silva, and C. Kendall. 2007. Nitrogen losses from dairy manure estimated through nitrogen mass balance or using markers. J. Dairy Science 90 (Suppl. 1): 162-162.
  • A.N. Hristov, S. Zaman, M. Vander Pol, P. Ndegwa, S. Silva, and C. Kendall. 2007. Nitrogen losses from dairy manure estimated through nitrogen mass balance or using markers. Poultry Science 86(Suppl. 1): 162-162.
  • A.N. Hristov, S. Zaman, M. Vander Pol, P. Ndegwa, S. Silva, and C. Kendall. 2007. Nitrogen losses from dairy manure estimated through nitrogen mass balance or using markers. J. Animal Science 85(Suppl. 1): 162-162.
  • Ndegwa, P.M., S.A.Thompson. 2002. Integrating composting and vermicomposting in the treatment and bioconversion of biosolids, Fuel and Energy Abstracts, 43(2): 120.
  • Ndegwa, P.M., S.A.Thompson, and K.C. Das. 2001. Optimising for worm use. Water21, 62(November/December): 269

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Refereed Journal Articles   |   Conference Papers & Presentations   |   Abstracts   |   Extension Publications

Extension Publications

  • Joo, H.S., P.M. Ndegwa, G.M. Neerackal, X. Wang, J.H. Harrison. 2015. Manure Management Practices for Mitigation of Gaseous Emissions from Naturally Ventilated Dairy barns. Proceedings for Waste to Worth 2015 “Advancing Sustainability in Animal Agriculture,” March 30 – April 3.
  • Neerackal, G.M., H.S. Joo, P.M. Ndegwa, J.H. Harrison. 2015. Mitigating Ammonia Emissions from Dairy Barns through Manure-pH Management. Proceedings for Waste to Worth 2015 “Advancing Sustainability in Animal Agriculture,” March 30 – April 3.
  • Wang, X., H.S. Joo, G.M. Neerackal, P.M. Ndegwa. 2015. Direct versus Indirect Methods for Ventilation Rates Measurement in Naturally Ventilated Livestock Buildings. Proceedings for Waste to Worth 2015 “Advancing Sustainability in Animal Agriculture,” March 30 – April 3.
  • Ndegwa P. 2014. Expert clarifies differences between human waste & livestock manure. Dairyland News, Yakima Valley and Whatcom Editions.
  • Ndegwa P. 2014. Composted livestock manure produces nutrient-rich crop, pasture and home garden organic fertilizer. Dairlyland News; Yakima Valley and Whatcom Editions.
  • 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.
  • 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.
  • 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.
  • Smith S., P. Ndegwa. 2012. Hydrogen Sulfide Concentrations in Biogas from Dairy Manure Digesters.
  • 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.
  • Ndegwa, P.M., & N. Embertson. 2011. Air Quality Best Management practices (BMPs) Selection Matrix. Dairy Air Quality Management Pilot Project.
  • Embertson, N., & P.M. Ndegwa. 2011. Best Management Practices (BMPs) Score Sheet. Dairy Air Quality Management Pilot Project.
  • Embertson, N., P.M. Ndegwa, G. Pruit, H. Tahat. 2011. Descriptions of Best Management Practices (BMPs). Dairy Air Quality Management Pilot Project.
  • Ndegwa, P.M., Embertson, N., & Harrison, J.H. (2011). Airborne cow allergen, ammonia and particulate matter at homes vary with distance to industrial scale dairy operations: an exposure assessment: D’Ann L Williams, Patrick N Breysse, Meredith C McCormack, Gregory B Diette, Shawn McKenzie and Alison S Geyh. Environmental Health, 2011, 10:72: Review/rebuttal.
  • Ndegwa, P.M., Joo, H.S., Harrison, J.H., Whitefield, E.M., Heber, A.J., & Ni, J.-. (2011). Impact of Anaerobic Digestion on Air Quality.
  • Ndegwa, P.M. 2009. Important Air Emissions from Dairy Operations vis-à-vis the Prevailing Federal Statutes (Handbook).
  • Ndegwa, P.M. 2008. “Mitigating Ammonia Emissions From Animal Agriculture, Streamed Video To access this segment via streamed video, click on the link and move the time slider (bottom of screen) to 40:00.
  • Ndegwa, P.M. 2008. AD101 – Nutrient Transformations, Nutrient Management, and Benefits (PPT).
  • Ndegwa, P.M. 2008. Livestock Industry: Environmental, Health & Legislation Issues (PPT).
  • Ndegwa, P.M., 2008. Ammonia and Particulate matter emissions from animal feeding operations (PPT).
  • Sheffield, R.E, M. Gamroth, P.M. Ndegwa. 2006. “Odor Management Plan for Northwest Pacific”: Idaho, Oregon, and Washington (PDF).
  • Sheffield, R.E., P.M. Ndegwa. 2006. Air Sampling for Agricultural Odors. Pacific Northwest Extension Bulletin (PDF).
  • Ndegwa, P.M. 2005. Managing ammonia emissions in a dairy (PDF).
  • Ndegwa, P.M., J.H. Harrison.2004. A Guide to preparation of “Odor Management Plans (PDF).”
  • Ndegwa, P.M., J.H. Harrison. 2004. An “Odor Management Template (PDF).”