Design of an Animal Waste Treatment System by Combination of Technologies

摘要

Animal feeding operations (AFOs) pose a number of risks to water quality and public health, due to the large amount of animal manure and wastewater that they generate. Manure from AFOs is rich in nutrients such as nitrogen (N), phosphorus (P), potassium (K), secondary nutrients, and metals such as copper. If not properly treated, excess nutrients can lead to eutrophication of surrounding water sources. The waste from AFOs also has the potential to contribute suspended solids, pathogens, oxygen-demanding materials, and heavy metals to surface and ground waters. In addition, AFOs can be a source of atmospheric pollutants, particularly ammonia, via volatilization. Handling of this waste is currently performed through (a) storage in lagoons and basins and (b) management using composting facilities, constructed wetlands, and application of manure or runoff water to agricultural land. The effectiveness (load reduction) of these practices is highly variable and requires strict controls to prevent water pollution. As the size and number of AFOs grow, so does the need for environmentally sound and economically efficient management practices. This manuscript describes a new system to overcome the problems with current animal waste handling and disposal methods. The proposed system combines and takes advantage of existing technologies such as an anaerobic digester and an aeration tank, and the recently developed Anammox reactor. The goals of this process are to (1) reduce the nitrogen content of manure waste, (2) generate low-cost energy, (3) reduce the odors and atmospheric contaminants, and (4) improve the overall quality of the liquid waste.