Nutrient Removal Structures Using Locally-Sourced Iron and Aluminum By-Products Reduce Nutrient Runoff from Broiler Production Facilities

摘要

A common issue with filters designed to remove nutrients from runoff is their reduced effectiveness in high-flow conditions. To overcome this challenge, it was determined that nutrient removal from broiler-house fan dust could be more effective if nutrient removal was conducted at the nutrient source. The objective of this study was to evaluate the effectiveness of containment trays (CTs) holding locally sourced by-products installed adjacent to broiler house fans at the University of Arkansas Savoy broiler production facility to capture nutrients released from dust during rainfall over four years (2013 to 2017). By-products used were locally sourced, iron-based red mud (RM) generated during the manufacture of steel belts for tires and alum-based drinking water treatment residual (WTR), where both materials have large phosphorus (P) sorption capacities. Four-year mean annual concentrations of dissolved P of through-flow from RM CTs were consistently below 0.7 mg·L~(-1) and below 1.6 mg·L~(-1) for WTR CT through-flow. This equated to an average 11- and 4-fold decrease for RM and WTR, relative to concentrations in runoff from same-sized plots adjacent to sidewall fans, demonstrating their potential to trap P at the source and decrease P runoff to nearby flowing waters. While there was no significant decline in RM or WTR effective-ness over the four-year study, further work needs to be conducted to determine the lifespan of CTs. Use of RM and WTR in CTs at poultry broiler production facilities, along with their subsequent land application, has the potential to reduce the amount of by-product materials that are currently landfilled.