Sulfuric acid could leak in salvage effort

Authorities are looking at two methods of salvaging a ship that sank on March 13 near the coast of southern Guangdong province, but they say there is no guarantee that the sulfuric acid it is carrying will not leak into the sea.

The Kenos Athena, a ship registered in South Korea, was carrying 7,000 metric tons of concentrated sulfuric acid and 140 metric tons of residual fuel oil when it sank in waters adjacent to Zhelang Island, according to a statement on the State Oceanic Administration's (SOA) website.

Authorities are considering two salvage plans, an official who declined to be named told China Daily on Tuesday.

One plan is to remove the sulfuric acid tank from the sunken vessel, then set the ship upright, and then pump it so that it will float. The other is to salvage the ship and then remove the sulfuric acid, the official said

But regardless of the method chosen, the acid could leak, and if it touches the water could even explode, the official said.

According to China Central Television reports, the plan to begin the salvage operation by removing the tank would take about 25 days, and the second plan would take about twice as long. The TV report said authorities are leaning toward the first plan, but no decision had been made.

The ship's owner and the insurance company arrived in Shanwei, Guangdong, to discuss the salvage operation and cost, according to the official.

A salvage ship would reach the area on Tuesday and await instructions, CCTV reported.

The vessel sank in a shipping lane and authorities are blocking vessels from coming within 2 nautical miles (3.7 kilometers) of the site.

Wu Jiancheng, a salvage expert in the Guangzhou salvage bureau of the Ministry of Transport, said at a news conference on Tuesday that he had never worked on salvaging a vessel carrying so much sulfuric acid and that there had been no comparable case for six decades.

Sulfuric acid reacts violently with water, releasing enormous heat, and a spill would change the pH value in the water, which could threaten marine plants and animals, a marine environment forecaster from the SOA surnamed Yuan told China Daily.

The movement of the water would gradually restore a normal pH value, but it would take time, he added.

The SOA's South China Sea Branch said on Thursday that "an oil slick" covering 5 to 6 square kilometers was seen on the ocean surface southwest of the wreck, and the slick contained a large amount of petroleum-related substance, indicating leakage from the vessel. No obvious change in the water's pH value had been detected as of Tuesday, according to the Guangdong's administration of ocean and fisheries.