Development & Aid, Environment, Tierramerica

Biological Clean-Up for Oil Spills

HAVANA, Aug 29 2005 (IPS) - A Cuban bio-product cleans up marine oil spills in just 30 days. Some five million barrels of fuel are moved each day through the Caribbean waters in tanker ships.

A product based on marine bacteria is being applied with success since 1992 in Cuba to clean up spills of petroleum products at sea, in freshwater and in soils.

Bioil-FC has proven effective in changing toxic compounds in hydrocarbons into biodegradable substances, up to complete conversion into carbon dioxide and water.

This bioproduct is inexpensive and its applications on this Caribbean island have shown high rates of effectiveness in brief periods, in comparison with other experiments around the world for treating hydrocarbon spills.

“We have achieved more than 90 percent remediation (clean up) in a maximum of 30 days of application,” chemical engineer Roberto Núñez, director of CEBIMAR, a marine biologicals research center, told Tierramérica.

In contrast, expert sources from various countries consider a satisfactory biological clean-up for spills of petroleum and derivatives to be 55 percent in three to four months.

“Bioremediation” is a technique for environmental detoxification through microorganisms that break down dangerous organic waste and turn it into less harmful compounds.

This method, available for the past 25 years, exploits the ability of some bacteria, yeast or molds to incorporate part of the dangerous compounds into their metabolism, for growth or for energy of the organism itself.

The Oceanology Institute of Cuba began 10 years ago to collect more than 400 strains of marine bacteria. Of that total, “70 percent are capable of degrading petroleum and five of them are very effective,” said Núñez.

Bioil-FC, formed from those five strains, was tested in the treatment of a 500-ton crude-oil spill in Cuba, caused in 1998 by a collision of two ships in Matanzas Bay, 98 km east of Havana.

According to CEBIMAR, “the ecosystem recovered completely” some 30 days after the application of 100,000 liters of Bioil-FC. The bay was left clean, as was Los Pinos beach, a popular swimming area for the local population.

“Cuba is surrounded by the sea and is always at risk of contamination from (marine spills) of petroleum,” said Núñez.

Some five million barrels of fuel move through the Caribbean Sea each day on tanker ships. The Caribbean region sees some of the most intensive maritime traffic in the world, with an average of 50,000 trips a year.

According to the United Nations Environment Program (UNEP), contamination from effluent from oil tankers and cruise ships is one of the most serious environmental threats to the largely impoverished countries of the Caribbean.

Bioremediation is usually employed as a secondary treatment after mechanical collection of oil waste using different types of equipment. That first phase can mean the recovery of up to 60 percent of the spilt hydrocarbon.

A “trial by fire” of sorts for CEBIMAR was the 2002 treatment of a 200-ton petroleum spill on a beach and mangrove marsh of Ensenada de Arroyo Blanco, in the eastern Cuban province of Holguín.

The experts were sent to the site two months after the accident. The petroleum had impregnated the marshland and had a 70 percent sedimentation rate, affecting six hectares of mangrove forest and four kilometers of beach.

“Never before had we used microorganisms without first having used equipment to collect the bulk of the spill. That was the first time in Cuba, and we began to see results within 48 hours,” said Núñez.

A scientific study of the Ensenada de Arroyo Blanco case indicates that the results helped “to perfect a new technology applicable for any type of hydrocarbon spill at these tropical latitudes.”

According to the report, “the geomorphological characteristics of the treated zone generalize the result for any type of coastal ecosystem” in climate conditions similar to Cuba's.

“The only limiting factor of Bioil-FC is that it acts only at temperatures above five degrees (Celsius). Maximum effectiveness is achieved between 25 and 35 degrees. At lower temperatures, it works, but slower,” explained Núñez.

Bioremediation for extremely cold climates, like Antarctica, has been developed since the beginning of the current decade by Argentine scientists, using autochthonous bacterial flora.