title: Phosphorus removal with by-products in a flow-through setting.
abstract: Phosphorus (P) losses to surface waters can result in eutrophication. Some industrial by-products have a strong affinity for dissolved P and may be useful in reducing nonpoint P pollution with landscape-scale runoff filters. Although appreciable research has been conducted on characterizing P sorption by industrial by-products via batch isotherms, less data are available on P sorption by these materials in a flow-through context integral to a landscape P filter. The objectives of this study were to evaluate several industrial by-products for P sorption in a flow-through setting, to determine material chemical properties that have the greatest impact on P sorption in a flow-through setting, and to explore how retention time (RT) and P concentration affect P removal. Twelve materials were characterized for chemical properties that typically influence P removal and subjected to flow-through P sorption experiments in which five different RTs and P concentrations were tested. The impact of RT and P concentrations on P removal varied based on material chemical properties, mainly as a function of oxalate-extractable aluminum (Al), iron (Fe), and water-soluble (WS) calcium (Ca). Statistical analysis showed that materials elevated in oxalate-extractable Al and Fe and WS Ca and that were highly buffered above pH 6 were able to remove the most P under flow-through conditions. Langmuir sorption maximum values from batch isotherms were poorly correlated with and overestimated P removal found under flow-through conditions. Within the conditions tested in this study, increases in RT and inflow P concentrations increased P removal among materials most likely to remove P via precipitation, whereas RT had little effect on materials likely to remove P via ligand exchange.
authors.affiliation: Oklahoma State Univ., Dep. of Plant and Soil Sci., Stillwater 47078-1020, USA.
authors.forename: Dustin
authors.initials: D
authors.lastname: Stoner
authors.forename: Chad
authors.initials: C
authors.lastname: Penn
authors.forename: Joshua
authors.initials: J
authors.lastname: McGrath
authors.forename: Jason
authors.initials: J
authors.lastname: Warren
mesh_terms: D002133:Calcium Sulfate / Q000737:chemistry; D060729:Coal Ash / Q000737:chemistry; D008956:Models, Chemical; D010758:Phosphorus / Q000737:chemistry*; D013997:Time Factors; D014867:Water / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D018508:Water Purification / Q000379:methods*
chemical_list: D060729:Coal Ash; D014874:Water Pollutants, Chemical; D014867:Water; D010758:Phosphorus; D002133:Calcium Sulfate