GREENHOUSE AND NUTRIENT BALANCE AS PART OF LIFE CYCLE ASSESSMENT (LCA) OF A COMMERCIAL AQUAPONIC FACILITY

Due to global populations continuing to grow at an unsustainable rate, methods of providing sufficient nutritious food and clean water must be developed all while reducing the negative environmental impacts of agricultural production systems.  Aquaculture, with its high feed conversion efficiency, has great potential to meet growing global demand for animal protein. However, aquaculture systems also produce large amounts of nutrient pollutants that can potentially degrade environmental quality if improperly managed.  Aquaponics presents a growing and viable solution to environmental shortcomings set forth by traditional aquaculture systems as it utilizes waste water from fish production in the production of traditional agricultural crops. Here, we look to quantify this statement by conducting a thorough life cycle assessment (LCA) of a semi-commercial scale aquaponic facility at Auburn University in Auburn, Alabama (Figure 1).

As a part of this on this ongoing assessment, extensive data has been collected in order to model and track the flow of nutrients through the system.  Initial findings have traced the flow and fate of nitrogen and phosphorous helping to identify which processes throughout the system contribute most to environmental impacts.  Using elemental analysis methods to provide real data from the system, a mass balanced nutrient flow model was created using the SuperPro Designer software model allowing for a virtual representation of the system. Additionally, extensive greenhouse gas sampling has taken place with initial findings identifying possible sites of high methane and nitrous oxide emissions (Table 1). We found high levels of methane emissions from the system's clarifiers and unusually levels of nitrous oxide from greenhouse crops grown in Dutch buckets. From these findings, we seek to further quantify these pollutant streams and begin to identify management methods to reduce such streams as part of a larger life cycle assessment.