2002b. Influence of water treatment residuals on phosphorus solubility and leaching

ABSTRACT pacity (Eghball et al., 1996). Areas of intense animal agri-culture of the Atlantic Coastal Plain are particularly sus-Laboratory and greenhouse studies compared the ability of water ceptible to deep leaching of P (Sims et al., 1998; Novaktreatment residuals (WTRs) to alter P solubility and leaching in Immo-kalee sandy soil (sandy, siliceous, hyperthermic Arenic Alaquod) et al., 2000). Because leached constituents can move to amended with biosolids and triple superphosphate (TSP). Aluminum surface water via lateral subsurface flow, controlling sulfate (Al-WTR) and ferric sulfate (Fe-WTR) coagulation residuals, labile P in porewaters is important in managing eutro-a lime softening residual (Ca-WTR) produced during hardness re- phication of surface waters. moval, and pure hematite were examined. In equilibration studies, Increased emphasis on soluble P losses from cropland the ability to reduce soluble P followed the order: Al-WTR has spawned the use of chemical amendments to immo-Ca-WTR ≈ Fe-WTR hematite. Differences in the P-fixing capacity bilize P in soils and land-applied wastes. Aluminum, Fe,of the sesquioxide-dominated materials (Al-WTR, Fe-WTR, hema-and Ca salts have been used to decrease P solubility intite) were attributed to their varying reactive Fe- and Al-hydrous poultry manure and runoff from manure-amended soilsoxide contents as measured by oxalate extraction. Leachate P was (Moore and Miller, 1994; Moore et al., 1999). Becausemonitored from greenhouse columns where bahiagrass (Paspalum notatum Flugge) was grown on Immokalee soil amended with biosol- alum (aluminum sulfate) and Fe salts are used to remov