Determination of Gas Emission Characteristics from Animal Wastes Using a Multiplexed Portable FTIR-Surface Chamber System

Livestock production is a growing source of air pollution at regional, national, and global scales. Improved livestock manure management has the potential to reduce environmental impacts; however, there is an urgent need for cost-efficient, reliable, and easy to maintain measurement and monitoring capabilities to precisely quantify emissions from livestock manure. This research describes and evaluates a novel measurement method based on the multiplexed portable Fourier Transform Infrared (FTIR) spectroscopy analyzer - surface chamber techniques for continuous measurements and monitoring gas emissions from manure sources. The multiplexing system was designed and developed to automate the chamber network, controlling the movement of chambers and accurately managing chamber air flow distribution. The measurement accuracy of the developed system was evaluated under controlled laboratory conditions. The result of the statistical hypothesis testing showed that there is no statistically significant differences among the measurement results from each of the twelve chambers. While microbial activity is a key factor for formation of gaseous compounds in manure, the magnitude of gas exchange between manure and the atmosphere largely depends on manure physical characteristics. A series of soil science measurement and modeling techniques were applied to determine a set of fundamental physical, hydraulics, and thermal properties of cattle manure to support advanced modeling of gas emissions from manure sources. The liquid water retention characteristic for cattle manure was found to be close to that of organic peat soils. The results also suggested that Richards equation can describe the hydrodynamics taking place in cattle manure relevant to natural drying processes. However, the uncertainties of the measurement results could be due to the complexity of shrinkage, surface crust formation, and shrinkage cracks. Carbon dioxide (CO2), methane (CH4), and ammonia (NH3) emissions were estimated and characterized in field plots using the developed gas emission measurement system. The measurements included four treatments; beef manure, dairy manure, beef compost, and dairy compost. The estimated CO2, CH4, and NH3 emissions from the surface application with dairy manure were the highest among other treatments, while those from the surface application with beef compost were the lowest. Impacts of temperature and water content on gaseous emissions were found to be correlated significantly. Overall, this dissertation provides a solid foundation upon which future research can build in better understanding and modeling animal waste emission processes that impact the environment

Modeling Temperature and Moisture Dependent Emissions of Carbon Dioxide and Methane From Drying Dairy Cow Manure

Greenhouse gas emissions due to biological degradation processes of animal wastes are significant sources of air pollution from agricultural areas. The major environmental controls on these microbe-induced gas fluxes are temperature and moisture content. The objective of this study was to model the effects of temperature and moisture content on emissions of CO2 and CH4 during the ambient drying process of dairy manure under controlled conditions. Gas emissions were continuously recorded over 15 d with paired fully automated closed dynamic chambers coupled with a Fourier Transformed Infrared gas analyzer. Water content and temperature were measured and monitored with capacitance sensors. In addition, on days 0, 3, 6, 9, 12 and 15, pH, moisture content, dissolved organic carbon and total carbon (TC) were determined. An empirical model derived from the Arrhenius equation confirmed high dependency of carbon emissions on temperature and moisture content. Results indicate that for the investigated dairy manure, 6.83% of TC was lost in the form of CO2 and 0.047% of TC was emitted as CH4. Neglecting the effect of temperature, the moisture contents associated with maximum gas emissions were estimated as 0.75 and 0.79 g*g-1 for CO2 and CH4, respectively

Temporal Variations in Greenhouse Gas Emissions from Dairy Cow Manure

Greenhouse and regulated gas emissions degrade air quality and contribute to environmental problems including acid rain and climate change. Gas emissions from animal feeding operations are of increasing concern as urban expansion encroaches on rural farming areas as well as due to increasing awareness of climate change. The major source of emissions in animal production sites is from animal waste (manure), which can be in solid, slurry, or liquid states, exhibiting varying physical properties. Once manure is excreted from an animal, processes of biological decomposition and formation of gaseous compounds continue, but diminish as the manure cools and dries. The types of gases generated and their emission rates are dependent on several variables, generally including animal species, feeding diets, and physical controls on gas emissions (i.e., temperature, manure’s water content and aeration). Focusing on the physical controls on gas emissions, we have designed and setup an experiment in a research greenhouse to investigate the impact of temperature and manure water content on gas emission rates. Our research initially aims to characterize individual gas emission rates from manure as a function of temperature, manure water content and time after excretion. The gas emission fluxes are determined with a closed-chamber method employing an automated LI-8100 chamber (LI-COR Biosciences, Lincoln, Neb.) and the gas concentrations are monitored with a Fourier Transform Infrared (FTIR) spectroscopy Gasmet DX-4030 analyzer (Gasmet Technology Oy, Helsinki, Finland). Evaporation rates, changes in manure water content, and temperature are also monitored during the experiment to define the degree of temporal variability affected by these factors. In our presentation, we will discuss the experimental design and setup, challenges, and results as well as potential application of the information gathered that will facilitate more simple and accurate estimation of gas emissions from animal feeding operations

Effectiveness of Manure Incorporation in Reducing Gas Emissions

Gas emissions from animal feeding operations (AFOs) create detrimental impacts on air quality ranging from short-term local effects, particularly odor, to long-term regional and global effects as greenhouse gas emissions. Best management practices (BMPs) have been designed and implemented to mitigate gas emissions to assist animal producers in addressing air quality impacts from farm operations. We examined an emission control strategy widely practiced in AFOs, incorporating manure immediately after surface application. The primary objectives were to evaluate the efficiency and identify improvement of the current BMPs for sustainable manure management. We simulated manure application and incorporation in a greenhouse to maintain moderate summertime temperatures (20 - 40 C) while monitoring gaseous emissions through the course of investigation. The dairy farmyard manure was collected from Caine Dairy Teaching and Research Center (Wellsville, UT). Closed dynamic chambers (CDC) coupled with a multiplexed Fourier Transformed Infrared (FTIR) spectroscopy gas analyzer (Gasmet DX-4030, Gasmet Technology Oy, Helsinki, Finland) provided gas emission estimates. The gas analyzer was capable of monitoring 15 pre-programmed gases simultaneously including typical gaseous compounds and greenhouse gases emitted from manure sources; namely, ammonia, carbon dioxide, methane, nitrous oxide, oxides of nitrogen, and volatile organic compounds. In this presentation, we will discuss the experimental design and setup, as well as the efficiency of the current available BMPs implemented to reduce air emissions on dairy operations, based on the gaseous emission monitoring during the course of our experiment. Results from our study should enhance development and implementation of more flexible and more efficient air quality management approaches for AFOs

Cumulative evaporation from manure surface application using a closed dynamic chamber technique

Considered one of the most effective best management practices, manure surface application aims at reducing the nutrient impacts of livestock operations on surface and ground waters. Manure and its use as fertilizer can also contribute to gaseous and particulate emissions, significantly degrading air quality to the detriment of human health and the environment. The objective of our study was to estimate water loss through surface evaporation from manure application. We established manure surface application plots at Greenville Research Farm (North Logan, UT) during the summer of 2013 to quantify gaseous emissions from four types of manure source (i.e. dairy manure, beef manure, dairy compost, and beef compost) and to investigate the temporal and spatial characteristics of the emissions. The temperature and relative humidity were monitored using a commercially available thermistor (10K ohm Yellow Bead Thermistor; Apogee Instruments, Logan, UT) and relative humidity sensor chip (HIH-4021-001; Honeywell, Minneapolis, MN) mounted inside each of 12-surface chambers. Soil/manure moisture contents were determined using dielectric sensors (GS3; Decagon Devices Inc., Pullman, WA). Experimental design and theoretical considerations for estimation of evaporative water loss using the dynamic changes in chamber relative humidity will be compared with water loss from the monitored soil moisture contents. Results from our study should enhance development and implementation of surface chamber-based assessment of water loss by demonstrating correlation between water vapor mass loss and surface moisture measurements

Modeling temperature and moisture dependent emissions of carbon dioxide and methane from drying dairy cow manure

Greenhouse gas emissions due to biological degradation processes of animal wastes are significant sources of air pollution from agricultural areas. The major environmental controls on these microbe-induced gas fluxes are temperature and moisture content. The objective of this study was to model the effects of temperature and moisture content on emissions of CO2 and CH4 during the ambient drying process of dairy manure under controlled conditions. Gas emissions were continuously recorded over 15 d with paired fully automated closed dynamic chambers coupled with a Fourier Transformed Infrared gas analyzer. Water content and temperature were measured and monitored with capacitance sensors. In addition, on days 0, 3, 6, 9, 12 and 15, pH, moisture content, dissolved organic carbon and total carbon (TC) were determined. An empirical model derived from the Arrhenius equation confirmed high dependency of carbon emissions on temperature and moisture content. Results indicate that for the investigated dairy manure, 6.83% of TC was lost in the form of CO2 and 0.047% of TC was emitted as CH4. Neglecting the effect of temperature, the moisture contents associated with maximum gas emissions were estimated as 0.75 and 0.79 g·g−1 for CO2 and CH4, respectively