An innovative technology exploring the feasibility of using the process of struvite (MgNH4PO4 *6H2O) formation/precipitation for nitrogen and phosphorous removal from lagoon effluents is proposed. Agricultural wastewater generated in concentrated animal production units has a number of contaminants that can adversely effect the water quality of receiving waters. Typical contaminants include very high concentrations of soluble and particulate organic matter as well as soluble inorganic and particulate organic nitrogen and phosphorous containing compounds. Left untreated, these wastes may render receiving water unsuitable for human and livestock consumption and negatively impact fisheries and the ecological health of the receiving water. Well maintained agricultural treatment techniques such as anaerobic lagoons and spray irrigation remove significant quantities of organic matter and typically convert most organic nitrogen and phosphorous to inorganic forms. Struvite precipitation has the potential to remove significant quantities of ammonium and phosphate typically found in high concentrations in livestock lagoon effluents and might recover some of the associated costs of this enhanced nutrient removal technology by forming a commercially useful by-product. Conventional nutrient removal systems may require multiple process steps, may remove only one nutrient constituent, produce a hazardous or nuisance residual, and are typically too expensive for most agricultural applications.
Anticipated Results/Potential Commercial Applications of Research: The proposed technology will provide an efficient and economic system for the agricultural industry enabling animal production operations to meet direct or indirect discharge water quality criteria. This is accomplished by integrating a novel physical-chemical process such as struvite crystallization within already existing treatment systems such as anaerobic lagoons. Whereas conventional technologies destroy or remove nitrogen and phosphorous with costly and often separate processes, this technology will be able to reuse these constituents as fertilizer. By making use of these resources the generally negative economics of wastewater treatment could be improved.
