POSTER PRESENTER: http://tinyurl.com/2024WSC-Cerroni CO-AUTHORS: Sean Babasin and Michael Holly, UW-Green Bay TITLE: Modified Phragmites biochar for phosphorus and nitrogen removal in agricultural runoff treatment systems ABSTRACT: In many wetland areas surrounded by residential or agricultural zones, the impact of nutrient-rich and polluted runoff is apparent. This study determined the effectiveness of biochar made from an invasive species (Phragmites australis, common reed grass) as a sustainable solution for removing dissolved phosphorus (P) and nitrogen (N) from runoff. Plants were sourced from an invasive lineage collected in residential wetland areas using a cut-stem approach with comprehensive seed capture to minimize the additional spread of the invasive species. The collected Phragmites material underwent initial processing using a hammer mill, followed by nitrogen gas purging and heating to produce biochar. Subsequent enhancements to the biochar included activation through potassium hydroxide and the introduction of specific metals. The modified biochar, serving as the carbon source in this activated carbon filtration system, was then tested to ascertain its performance as a filtration medium for agricultural runoff. Phragmites australis biochar shows potential in removing dissolved phosphorus and nitrogen from runoff. Utilization of this organic material in future filtration products could complement current management practices of the invasive species, potentially providing additional economic incentives. BIO: Not submitted.