Natural cleanup of heavy fuel oil on rocks: an in situ experiment

ABSTRACT Following the bombardment of the Jyeh power station in Lebanon on July 16 2006, about 10 to 15000 tons of heavy fuel oil drifted 150 km northward all the way to the Syrian border. Because of the continuing war, the cleanup operations could not start until early September. The response consisted of conceptually dividing the coast line into several sectors managed by various operators; from Jyeh to Beyrouth, a 34.5 km stretch of shoreline, the treatment of beaches was assigned to the lebanese N.G.O “Bahr Loubnan’. In this area, 5.3 km of sandy and gravel beaches appeared to be heavily oiled on a width that seldomly exceeded 10 m. Oil was found buried down to a depth of 1.8 m at several locations. Additionnally oil was also found sunken in shallow waters in the breaker zones of numerous beaches. In order to minimize sediment removal and production of oily waste to be treated, it was decided to operate massive treatmenN in situ. After manual recovery of stranded oil, about 12,000 m of sediment including 1,000 m of cobbles have been relocated in the surf zone. Despite the lack of tides and of the generally calm weather conditions, surfwashing was very efficient due mainly to the fact that, in non tidal conditions, sediments are continuously reworked by wave açtion which operates at the same level on the beaches. Only 540 m of heavily oiled sand, was removed from beaches and submitted for further treatment. The lack of appropriate sorbents material in Lebanon to capture the floating oil released by surfwahing was also a challenge. This was addressed by using locally Nmanufactured sorbents, which proved to be very efficient and 60 m of sorbent soaked with oil were produced during the cleanup.

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Comparative toxicity assessment of in situ burn residues to initial and dispersed heavy fuel oil using zebrafish embryos as test organisms

Environmental Science and Pollution Research ◽

10.1007/s11356-020-11729-5 ◽

2020 ◽

Author(s):

Sarah Johann ◽

Mira Goßen ◽

Leonie Mueller ◽

Valentina Selja ◽

Kim Gustavson ◽

...

Keyword(s):

Scientific Information ◽

Fuel Oil ◽

Zebrafish Embryos ◽

Life Stages ◽

Biological Organization ◽

Heavy Fuel Oil ◽

Toxic Response ◽

Chemical Dispersant ◽

The Impact

AbstractIn situ burning (ISB) is discussed to be one of the most suitable response strategies to combat oil spills in extreme conditions. After burning, a highly viscous and sticky residue is left and may over time pose a risk of exposing aquatic biota to toxic oil compounds. Scientific information about the impact of burn residues on the environment is scarce. In this context, a comprehensive ISB field experiment with approx. 1000L IFO 180 was conducted in a fjord in Greenland. The present study investigated the toxicity of collected ISB residues to early life stages of zebrafish (Danio rerio) as a model for potentially exposed pelagic organisms. The toxicity of ISB residues on zebrafish embryos was compared with the toxicity of the initial (unweathered) IFO 180 and chemically dispersed IFO 180. Morphological malformations, hatching success, swimming behavior, and biomarkers for exposure (CYP1A activity, AChE inhibition) were evaluated in order to cover the toxic response on different biological organization levels. Across all endpoints, ISB residues did not induce greater toxicity in zebrafish embryos compared with the initial oil. The application of a chemical dispersant increased the acute toxicity most likely due to a higher bioavailability of dissolved and particulate oil components. The results provide insight into the adverse effects of ISB residues on sensitive life stages of fish in comparison with chemical dispersant application.

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Flume Experiments to Assess the Effect of Bottom Roughness, Temperature, Water Velocity and Oil Condition on Critical Shear Stress Estimates of Heavy Fuel Oil

International Oil Spill Conference Proceedings ◽

10.7901/2169-3358-2021.1.1141591 ◽

2021 ◽

Vol 2021 (1) ◽

Author(s):

MELISSA GLOEKLER ◽

NANCY KINNER ◽

TOM BALLESTERO ◽

ESHAN DAVE

Keyword(s):

Shear Stress ◽

Critical Shear Stress ◽

Maximum Velocity ◽

Water Velocity ◽

Fuel Oil ◽

Bed Shear Stress ◽

Heavy Fuel Oil ◽

Kaolinite Clay ◽

Sunken Oil

Non-floating oil is challenging to detect, track, and recover due to limited visibility inhibiting verification of the oil's location and subsurface movement. Oil that sinks to the bottom (i.e., sunken oil) can form large mats or small agglomerates on the bottom, mix into sediments, or remobilize into the water column and move with currents potentially impacting shorelines, benthic and pelagic organisms, intakes for drinking water, and power plants. Trajectory models exist that predict movement of floating and submerged oil; however, many models cannot accurately address sunken oil movement because the bed shear stress (BSS) necessary to mobilize oil (i.e., critical shear stress (CSS)), neglects the effects of bottom roughness and assumes an immobile bed. The goal of this research is to provide responders and modelers with more precise CSS estimates that include the effect of bottom roughness and incorporate results into a response tool to predict sunken oil movement. The transport of oil depends upon in-situ environmental conditions and oil properties. This research used the Coastal Response Research Center's (CRRC) 2180-liter straight flume to test the effects of water velocity, water temperature, oil mass, and bottom friction on fresh and weathered No. 6 Heavy Fuel Oil (HFO) on an immobile boundary. The flume's test section provided a uniform, one-dimensional flow field measured in 3D by an acoustic Doppler velocimeter (ADV), a Nortek AS (Norway) Vectrino II Profiling Velocimeter. The fresh or weathered (%Ev=5) HFO was mixed with kaolinite clay as a sinking agent, and 100 grams of the mixture was injected into static water via subsurface injection. The water velocity was incrementally increased in a stepwise manner by 0.07 m/s intervals and held for 15 minutes at each velocity. This occurred until: (1) oil had stopped eroding or was completely eroded from the substrate, or (2) the maximum velocity of 1.04 m/s was reached. Bottom roughness was evaluated using the velocity profile and bed shear stress (BSS) was calculated using multiple methods applicable to lab and field conditions. The oil's behavior was documented by downward- and side-facing GoPro cameras and reviewed to estimate mass loss per velocity interval, the distance the oil migrated along the bottom, and the corresponding CSS. In the case of an oil spill, responders can compare CSS estimates, determined through this research, with in-situ BSS estimates predicting under what conditions the sunken oil will become mobile.

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