PW13 Sediment Chemistry
Exhibit Hall
8:00 AM - Wednesday, 12 November 2003
(PW205) Phytate Sorption to Highly Weathered Soils and Sediment.
Kelsey-Wall, A1, Seaman, J1, Jackson, B1, Hutchinson, J1, 1 Savannah River Ecology Laboratory - UGA, Aiken, SC, United States
ABSTRACT- Phytate is present in high concentrations in plant material because it is a major source of phosphorus (P) storage in plants. Animal feeds contain high concentrations of phytate. Since many animals lack phytase, the enzyme used to breakdown phytate, significant amounts of phytate remain unchanged through digestion. Phytate, the most abundant form of organic phosphorus found in animal manures, plays a major role in nutrient cycling and eutrophication. Once animal manures are applied to soil for fertilization, phytate can leach from the manure into the soil, or can be possibly lost to runoff and erosion. This study looks at sorption of phytate to a synthetic mineral analog, goethite, a surface soil, and a subsurface soil at concentrations representative of what is found in soils amended with animal manure. Batch isotherms were performed using an artificial rain water (ARW) background solution to determine sorption mechanisms of phytate for each substance. Column studies were performed, also using an ARW background, to examine the sorption of phytate under kinetically limiting conditions. The method of determination for phytate couples an inductively-coupled-plasma-mass-spectrometer (ICP-MS) for detection of P along with ion-chromotography for P-species separation. Comparisons are made for both batch and dynamic sorption of phytate to each material.
Key words: Inositol Hexaphosphate, Phytate, Organic Phosphorus, Animal Manure