- Accident date
- Accident area
- Trevo's terminal, Rio Grande
- Spill area
- Cause of spill
- Structural damage
- Quantity transported
- 19, 000 tonnes
- Nature of pollutant
- 95 % sulphuric acid
- Ship / structure type
- Chemical tanker
On 24 July 1998, the chemical tanker Bahamas entered the port of Rio Grande in Brazil loaded with 19,000 tonnes of 95% sulphuric acid.
As a result of certain technical errors and a crisis situation onboard the vessel due to the delapidated state of the vessel, the engine room became flooded with a mixture of water and acid. This highly corrosive mixture created serious problems for the vessel's structure.
By 30 August, the vessel had developed a considerable list and the acid had reached the generators. The crew abandoned ship for fear of explosion. Jets of liquid were observed spurting out of the tanks and the pump room, composed of water and acid. The company Smit Tak was contracted by the shipowners to pump part of the cargo to land. However, the acid and water mixture was too corrosive and destroyed the hose.
The problematic factors for response were:
- the high risk of explosion caused by the generation of hydrogen
- the absence of a suitable tank on land to hold the corrosive water and acid mixture
- the corrosion of the ship’s structures which could lead to the leaching of heavy metals in the environment
- the location of the accident in a port, making it impossible to neutralize such an large quantity of acid
On 22 October 1998, the decision was made to gradually discharge the cargo from the vessel, at outgoing tide, into the port, while constantly monitoring the pH. The pumping operation lasted more than eleven days, without ever exceeding the agreed pH limits and without the leaching of ferric compounds from the hull.
On 20 April 1999, by which time the vessel had been emptied of its cargo, the Bahamas was scuttled in international waters upon the decision of the maritime authorities.
FURG, Department of Geology, Rio Grande, Brazil, The effect of accidental sulphuric acide leaking on metal distributions in estuarine sediment of Patos Lagoon.