Selection of Nutrients to Enhance Biodegradation for the Remediation of Oil Spilled on Beaches1

Abstract

Laboratory studies were conducted to determine the fate of fertilizers proposed for application to the Alaska shoreline in support of the Alaskan Oil Spill EPA Bioremediation Project. Fertilizer application is thought to provide indigenous organisms with nutrients that appear to be limited on ocean beaches. The experiments were developed strictly to test the durability, release rates, and application procedures of a variety of fertilizer types. The effects of tidal movement on a beach were simulated by two separate conditions, static and dynamic. The static condition represented periods when the beach material was under water and turbulence was at a minimum. This condition was simulated in the laboratory by submerging the nutrient in a beaker of simulated seawater (with or without beach material, depending on the nutrients being tested). These experiments ran continuously over a three-month period, with water exchanges according to a planned schedule. Nutrient concentrations were measured in the exchanged water. Dynamic conditions represented the forces on beach material as the water moved from low to high tide and back to low tide. In the laboratory, the condition was simulated by applying the nutrients to beach material piled in one end of a long, narrow tray placed on a rocker table. When the rocker table was operating and enough seawater had been added to cover the beach material (in the rocker table's low position), a gentle sloshing of the water over the materials resulted. These experiments generally lasted one to two hours, during which time liquid samples were collected for nutrient analyses. Durability of the fertilizers was measured by visual observation and freeze/thaw determinations. The experimental setup was economical and performed well. The fertilizer most suited for field trial was found to be isobutyraldehyde diurea briquettes, which produced a slow, continuous release of nutrients.

Bioremediation of Oil on Shoreline Environments: Development of Techniques and Guidelines

“…Failure of the bioremediation treatment was attributed to the rapid loss of nutrients and an acute toxic response by the natural microflora to 'unweathered' condensate. Similar losses of this oleophilic nutrient from oiled sediments have been subsequently observed in laboratory studies [31] and field trials [32].…”

“…In this instance, bioremediation was adopted as a prime cleanup strategy. Following laboratory experiments which demonstrated the potential for bioremediation [5,53], laboratory and field experiments were conducted to evaluate the effectiveness of bioremediation agents that included an oleophilic fertilizer [7,15,54], dissolved water-soluble [5,54] and slow-release inorganic fertilizer formulations [5,7,31], and microbial inocula [21]. By measuring changes over time in the oil composition, relative to hopane, a stable high-molecular weight hydrocarbon present in the oil when spilled, the rate and extent of oil biodegradation was quantified with a high level of statistical confidence.…”

Oil spill bioremediation: experiences, lessons and results from the Exxon Valdez oil spill in Alaska

“…~ apply over a large surface area and were found to adhere tightly to the oiled beach material and worked their way down under the cobble where they were difficult to dislodge. Nutrient release characteristics, which were determined in simple laboratory test systems (Safferman 1992;Glaser et al 1991), showed that much of the nitrogen (ammonia and nitrate) and phosphorus (phosphate) released from the granules occurred in the first 24-72 hours. However, sufficient quantities continued to be released steadily for a considerable time thereafter.…”

Evaluation of Petroleum Oil Degrading Mixed Microorganism Agent for the Bioremediation of Petroleum Oil Spilled in Marine Environments

“…유류에 오염된 토양환경을 정화하기 위한 생물정화기술 (Bioremediation)은 토착미생물에 의한 유류화합물의 분해를 가속시킬 수 있는 물질 또는 유류분해미생물을 첨가하거나 조작하는 기술을 일컫는다 [3,4,12,19].…”