Evaluation of Floating Treatment Wetlands in Stormwater Retention Ponds On Poultry Farms to Reduce Nutrient Loading.

Excess nutrient loads have the potential to cause eutrophication. Best management practices (BMPs) such as stormwater retention ponds are implemented to collect runoff and drainage from poultry farms and provide a possible intervention point for the treatment of water. Utilization of floating treatment wetlands (FTWs), within these systems could remove excessive nutrients from water. Biohaven® FTWs are man-made recycled plastic (HDPE) matrices that are similar to attached growth media filters. Macrophytic plants installed on FTWs allow bacterial and algal colonization. The combination of organisms removes nutrients from the surrounding water column, effectively reducing concentrations. FTWs provide a new tool that may assist in the uptake of nutrients, especially those that are commonly associated with eutrophication. However, FTWs have only been marginally evaluated and compared to other treatment wetland systems in effectiveness. The majority of research conducted on FTWs focuses on nutrient removal via plant uptake. The results of prior studies conclude that plant uptake of nutrients alone is not a reliable source of nutrient removal because macrophytes and microalgae only temporarily immobilize N; this conclusion suggests that without periodic harvesting of plants, nutrients would return to the system upon nutrient cycling through plant decomposition, while the permanent removal of N is dependent upon denitrification. The goal of this study is to evaluate the overall nutrient (N & P) uptake of plants, FTW matrix, as well as denitrification throughout the FTW. Denitrification will be evaluated through a denitrification enzyme assay (DEA) which measures the maximum potential of microbes at sample collection. N & P concentrations will be evaluated via colormetric, ICP and carbon, hydrogen, nitrogen (CHN) combustion analysis. Beyond the use of FTWs in confined animal feeding operation (CAFO) production areas, information gained from the proposed research will provide a basis to reduce surface nutrient pollution for other Mid-Atlantic watersheds.