title: Evaluation of a universal flow-through model for predicting and designing phosphorus removal structures.
abstract: Phosphorus (P) removal structures have been shown to decrease dissolved P loss from agricultural and urban areas which may reduce the threat of eutrophication. In order to design or quantify performance of these structures, the relationship between discrete and cumulative removal with cumulative P loading must be determined, either by individual flow-through experiments or model prediction. A model was previously developed for predicting P removal with P sorption materials (PSMs) under flow-through conditions, as a function of inflow P concentration, retention time (RT), and PSM characteristics. The objective of this study was to compare model results to measured P removal data from several PSM under a range of conditions (P concentrations and RT) and scales ranging from laboratory to field. Materials tested included acid mine drainage residuals (AMDRs), treated and non-treated electric arc furnace (EAF) steel slag at different size fractions, and flue gas desulfurization (FGD) gypsum. Equations for P removal curves and cumulative P removed were not significantly different between predicted and actual values for any of the 23 scenarios examined. However, the model did tend to slightly over-predict cumulative P removal for calcium-based PSMs. The ability of the model to predict P removal for various materials, RTs, and P concentrations in both controlled settings and field structures validate its use in design and quantification of these structures. This ability to predict P removal without constant monitoring is vital to widespread adoption of P removal structures, especially for meeting discharge regulations and nutrient trading programs.
authors.affiliation: Department of Plant and Soil Science, Oklahoma State University, 367 Agricultural Hall, Stillwater, OK, 74078, USA. Electronic address: chad.penn@okstate.edu.
authors.forename: Chad
authors.initials: C
authors.lastname: Penn
authors.affiliation: Department of Plant and Soil Science, Oklahoma State University, 367 Agricultural Hall, Stillwater, OK, 74078, USA; Department of Plant and Soil Science, University of Kentucky, 1405 Veterans Drive, Lexington, KY, 40546, USA.
authors.forename: James
authors.initials: J
authors.lastname: Bowen
authors.affiliation: Department of Plant and Soil Science, University of Kentucky, 1405 Veterans Drive, Lexington, KY, 40546, USA; Department of Environmental Science and Technology, University of Maryland, 0214 H.J. Patterson Hall, College Park, MD, 27042, USA.
authors.forename: Joshua
authors.initials: J
authors.lastname: McGrath
authors.affiliation: School of Civil Engineering and Environmental Science, University of Oklahoma, 202 W. Boyd St. Room 334, Norman, OK, 73019, USA.
authors.forename: Robert
authors.initials: R
authors.lastname: Nairn
authors.affiliation: Department of Plant and Soil Science, Oklahoma State University, 367 Agricultural Hall, Stillwater, OK, 74078, USA.
authors.forename: Garey
authors.initials: G
authors.lastname: Fox
authors.affiliation: Department of Plant and Soil Science, Oklahoma State University, 367 Agricultural Hall, Stillwater, OK, 74078, USA.
authors.forename: Glenn
authors.initials: G
authors.lastname: Brown
authors.affiliation: Department of Plant and Soil Science, Oklahoma State University, 367 Agricultural Hall, Stillwater, OK, 74078, USA.
authors.forename: Stuart
authors.initials: S
authors.lastname: Wilson
authors.affiliation: Department of Environmental Science and Technology, University of Maryland, 0214 H.J. Patterson Hall, College Park, MD, 27042, USA.
authors.forename: Clinton
authors.initials: C
authors.lastname: Gill
mesh_terms: D000327:Adsorption; D016573:Agrochemicals / Q000737:chemistry; D002133:Calcium Sulfate / Q000737:chemistry*; D005374:Filtration; D008906:Mining; D008962:Models, Theoretical; D010758:Phosphorus / Q000032:analysis* / Q000737:chemistry; D061005:Ponds / Q000737:chemistry; D013232:Steel / Q000737:chemistry*; D014481:United States; D014872:Water Movements; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry; D018508:Water Purification / Q000379:methods*
chemical_list: D016573:Agrochemicals; D014874:Water Pollutants, Chemical; D013232:Steel; D010758:Phosphorus; D002133:Calcium Sulfate
keywords: Eutrophication; Flow-through model; Legacy phosphorus; Phosphorus; Phosphorus removal structures; Phosphorus sorption materials