Photolysis of 2, 4, 6-trinitrotoluene in seawater and estuary water: Impact of pH, temperature, salinity, and dissolved organic matter. Issue 2 (30th January 2017)

• Record Type: Journal Article
• Authors: Luning Prak, Dianne J.; Breuer, James E.T.; Rios, Evelyn A.; Jedlicka, Erin E.; O'Sullivan, Daniel W.
• Is Part Of: Marine pollution bulletin. Volume 114:Issue 2(2017:Jan.)
• Page Start: 977
• Page End: 986
• Publication Date: 2017-01-30
• Subjects: Explosives -- Ultraviolet radiation -- Nitrogen compounds -- Photochemistry; Marine pollution -- Periodicals; Marine Biology -- Periodicals; Water Pollution -- Periodicals; Mer -- Pollution -- Périodiques; Publications périodiques; Pollution des mers; Lutte antipollution; Electronic journals; 363.7394
• DOI: 10.1016/j.marpolbul.2016.10.073
• Languages: English
• ISSNs: 0025-326X

Abstract

Abstract: The influence of salinity, pH, temperature, and dissolved organic matter on the photolysis rate of 2, 4, 6-trinitrotoluene (TNT) in marine, estuary, and laboratory-prepared waters was studied using a Suntest CPS +® solar simulator equipped with optical filters. TNT degradation rates were determined using HPLC analysis, and products were identified using LC/MS. Minimal or no TNT photolysis occurred under a 395-nm long pass filter, but under a 295-nm filter, first-order TNT degradation rate constants and apparent quantum yields increased with increasing salinity in both natural and artificial seawater. TNT rate constants increased slightly with increasing temperature (10 to 32 °C) but did not change significantly with pH (6.4 to 8.1). The addition of dissolved organic matter (up to 5 mg/L) to ultrapure water, artificial seawater, and natural seawater increased the TNT photolysis rate constant. Products formed by TNT photolysis in natural seawater were determined to be 2, 4, 6-trinitrobenzaldehyde, 1, 3, 5-trinitrobenzene, 2, 4, 6-trinitrobenzoic acid, and 2-amino-4, 6-dinitrobenzoic acid. Graphical abstract: Highlights: 2, 4, 6-trinitrotoluene (TNT) was photolyzed in marine, estuary, & laboratory waters. TNT photolysis rates increased with increasing salinity & dissolved organic matter. Temperature and pH had minimal impact on TNT photolysis in marine waters. In seawater, TNT photolysis produced 1, 3, 5-trinitrobenzene & trinitrobenzaldehyde. Polar products were 2, 4, 6-trinobenzoic acid & 2-amino-4, 6-dinitrobenzoic acid.