Surface aeration to reduce odor generation potential in swine manure lagoons

The odors originating from open liquid manure storages are one of the most persistent problems and present undesirable environmental situations that have caused conflicts between swine producers and their neighboring communities. A considerable amount of research effort has been spent on controlling odor emissions from swine manure storages with methods studied including aeration and anaerobic treatment. Surface aeration is the most cost-effective method. Therefore, more information is needed about the system improvement and optimal depth determination of surface aeration.;This thesis presents investigations on gas injection in water, including a field-and-lab-scale study on surface aeration to reduce odor generation potential and laboratory-scale studies on aerator module development, liquid flow rate, alpha factor, surface aeration depth and temperature profiles on aeration efficiency. The purpose of the first investigation was to evaluate the effectiveness of a surface aeration system using venturi injectors, in which air was injected into a pipeline and discharged into the lagoon as a gas-liquid diffuser. This technique was shown to be an effective means of improving the dissolved oxygen levels and reduce odor generation potential in the lagoon. The purpose of the laboratory investigation was to better understand the effect of liquid flow rate, aerator module design, surface aeration depth and temperature on the surface aeration efficiency. Important fundamental results obtained in this thesis such as the field-scale surface aeration study and optimal surface aeration depth were very useful for many engineering applications, and pave the way for all animal producers (not just swine) who use liquid manure storages to adopt advanced aeration technologies for controlling manure odors.;Keywords: Aerator module development; Alpha factor; Diffuser submergence; Liquid flow rate; Odor reduction; Surface aeration; Temperature profile.