Picric Acid Degradation in Sediments from the Louisiana Army Ammunition Plant

• Published in: Water, air, and soil pollution Vol. 177; no. 1-4; pp. 169 - 181
• Main Authors: Tan, Y, Davidson, G.R, See, C.H, Dunbar, D.C, O'haver, J.H, Rice, S, Harrelson, D.W, Zakikhani, M
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer 01-11-2006; Springer Nature B.V
• Subjects: Acids; adsorption; Ammunition; Applied sciences; aquifers; Biodegradation; Biological and physicochemical properties of pollutants. Interaction in the soil; carbonates; clay; Degradation; duration; Earth sciences; Earth, ocean, space; Engineering and environment geology. Geothermics; Environmental monitoring; Exact sciences and technology; explosives; freshwater; Grain size; Microbial activity; Microorganisms; Monitoring; nitrates; Nitrites; organic matter; Picric acid; Pollution; Pollution, environment geology; sediment contamination; Sediments; Slurries; Soil and sediments pollution; Soil pollution; water pollution; Louisiana; United States; North America; America; USA, Louisiana; Biodegradation; Microbial activity; Nitro compound; Pollutant behavior; LAAP; Environmental factor; degradation; Soil pollution; Sediments; natural attenuation; Selfpurification; Ammunition; Phenols; Picric acid; Explosives; Degradation product; Armament; 2,4,6-trinitrophenol
• ISSN: 0049-6979; 1573-2932
• DOI: 10.1007/s11270-006-9133-y

Picric acid is an explosive historically produced and disposed at the Louisiana Army Ammunition Plant (LAAP) in northern Louisiana. The potential for natural degradation of picric acid was investigated by creating picric-acid slurries with four LAAP sediments of variable composition and monitoring for up to 98 days. The concentrations of picric acid decreased rapidly in all slurries during the first day, attributed to adsorption, followed by slower decreases in some samples due to degradation. Degradation in unsterilized slurries was nearly complete within 80 days for two of the four sediments. Increases in nitrite and nitrate concentration over time were proportional to the loss of picric acid and indicate that at least two of the three nitrite groups were removed from the picric acid molecule. The absence of significant concentrations of compounds with a mass greater than 100 amu in the final solutions suggests that all three nitrite groups were removed. No correlation was found between the degree of degradation and grain size, clay content, organic content, carbonate content, or a suite of element concentrations in the sediment. Degradation in sterilized samples was minimal for all sediment slurries, indicating microbial activity as the primary mechanism of degradation.