Solid-State Speciation of Natural and Alum-Amended Poultry Litter Using XANES Spectroscopy

• Published in: Environmental science & technology Vol. 36; no. 20; pp. 4253 - 4261
• Main Authors: Peak, D, Sims, J. T, Sparks, D. L
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 15.10.2002
• Subjects: Agriculture, rearing and food industries wastes; Alum Compounds - chemistry; Animal reproduction; Animals; Applied sciences; Chemical Precipitation; Exact sciences and technology; Manure; Phosphates; Phosphates - chemistry; Pollution; Poultry; Refuse Disposal - methods; Spectrum analysis; Spectrum Analysis - methods; Wastes; Phosphates; Amendment; XANES spectrometry; Pollutant behavior; Reaction mechanism; Agricultural waste; Farmyard manure; Rearing by-product; Speciation; Aluminium sulfate; Poultry farming
• ISSN: 0013-936X; 1520-5851
• DOI: 10.1021/es025660d

While alum amendments have shown to be effective in lowering water-soluble phosphate levels in poultry litter, the mechanism by which this occurs is not fully known. To determine the solid-state speciation of phosphate in litter samples, experiments were conducted with X-ray absorption near edge structure (XANES) spectroscopy. XANES analysis reveals that, in unamended samples, phosphate is present as weakly bound inorganic as well as some organic phosphate, with some dicalcium phosphate-type calcium phosphates also present. When alum is applied in the houses, XANES results suggest that it precipitates out as amorphous Al(OH)3 and then reacts with phosphate via an adsorption mechanism. No evidence was found of aluminum phosphate precipitation in any samples.