Explosives in seawater

Figure 1. Seawater and the Thames Flood Barrier

BGS organic geochemists have been conducting laboratory experiments to assess the rate of degradation of 2,4,6-trinitrotoluene (TNT) in seawater. The experiments, designed to simulate conditions commonly encountered in the North Sea, involved shaking seawater in the presence of clay- and sand-rich sediments to assess how quickly TNT degraded. The developed methodology was used to track changes in TNT concentration at seven intervals over 120 days.

TNT in the environment

Substantial dumping of unexploded ordnance at sea has occurred worldwide, with considerable amounts deposited in UK coastal waters, including the North Sea. Conventional explosives such as TNT and associated breakdown products are known to be toxic to benthic littoral organisms and therefore represent a threat to coastal and marine ecosystems.

Influence of sediments and microbes

Analysis of the seawater revealed that TNT was rapidly attenuated by clay sediments and that the presence of microbes speeded up the loss of TNT. In contrast, the loss of TNT was slower in seawater when sandy sediment was present or when there was no microbial activity.

The study showed that under winter conditions in the North Sea, TNT dissipated at a slower rate than previously reported.

Further information

Harrison, I and Vane, C H. 2010. Attenuation of TNT in seawater microcosms. Water Science Technology, 61 (10), 2531—2538.

Contact

Please contact Dr Chris Vane for further information