Gallons Of Dispersants Research Articles

Impact of dispersant on early life stages of the water flea Daphnia magna and the eastern oyster Crassostrea virginica.

In response to the 2010 Deepwater Horizon oil spill, over 1 million gallons of dispersant were applied in Gulf of Mexico offshore waters; Corexit 9500 was the most applied dispersant. The impact on organisms in nearshore and freshwaters has received little scrutiny. Acute 48 h toxicity of Corexit 9500 and a new hyperbranched polyethylenimine (HPEI) dispersant-like compound were evaluated for the freshwater indicator organism, Daphnia magna and for larval and early spat stages of the Eastern oyster, Crassostrea virginica. For D. magna, Corexit 9500 demonstrated toxicity (EC50 of 0.14 [0.13, 0.15] ppm) similar to the 10-kDa HPEI (EC50 of 0.16 [0.12, 0.19] ppm). HPEI toxicity increased as a function of molecular weight (1.2 to 750kDa). The 10 kDa size HPEI was further investigated because it dispersed crude oil with equal effectiveness as Corexit. For Corexit, 100% oyster mortality was detected for the ≤0.2-mm size classes and mortality >50% for the 0.3- and 0.7-mm size classes at the two greatest concentrations (25 and 50ppm). HPEI (10kDa) exhibited low mortality rates (<30%) for all concentrations for all oyster size classes except the 0.1-mm class. Although mortality rates for this size class were up to 60%, mortality was still less than the mortality caused by Corexit 9500. The low toxicity of HPEI polymers for C. virginica in comparison with Corexit 9500 suggests that HPEI polymers warrant further study.

Advancements in Crude Oil Spill Remediation Research After the Deepwater Horizon Oil Spill

An estimated 4.9 million barrels of crude oil and natural gases was released into the Gulf of Mexico during the Deepwater Horizon oil spill of 2010. The Deepwater Horizon oil spill affected the aquatic species in the Gulf of Mexico, vegetation, and the human population along the coast. To reduce the effect of the spilled oil on the environment, different remediation strategies such as chemical dispersant, and mechanical booms and skimmers were utilized. Over 2.1 million gallons of dispersants was applied to minimize the impact of the spilled oil. However, environmental and human toxicity issues arose due to the perceived toxicity of the dispersant formulations applied. After the Deepwater Horizon oil spill, various studies have been conducted to find alternative and environmentally benign oil spill response strategies. The focus of this manuscript is to demonstrate an objective and an overall picture of current research work on oil spill response methods with emphasis on dispersant and oil sorbent applications. Current trends in oil spill sorbent and dispersant formulation research are presented. Furthermore, strategies to formulate environmentally benign dispersants, as well as the possible use of photoremediation, are highlighted.

Ultrasonic Scattering Measurements of Dispersed Oil Droplets in the Presence of Gas

ABSTRACT To help minimize the effects of oil spills on marine environments, chemical dispersants are used to disperse the oil in the water column so the oil can be consumed by naturally occurring bacteria. During the Deepwater Horizon incident, 1.1 million gallons of dispersant were injected directly into the flowing plume of oil and natural gas over 1500 meters deep. Dispersant's main effect is to decrease the surface tension at the oil-water interface causing the oil to form droplets smaller than ~70 microns so they can remain in the water column. Currently the efficacy of aerial applied dispersants on surface slicks is determined by measuring the droplet size decrease using a Laser In-Situ Scattering Transmissometer (LISST) or by detecting the oil in the water column using fluorometers. LISST instruments are limited to dilute mixtures, below ~500 ppm, because the LISST signal saturates for concentrated mixtures, and their windows can become occluded by oil and biofilms. Fluorometers only measure oil concentration; thus they cannot distinguish between naturally dispersed oil droplets, which can float back to the surface, from chemically dispersed oil droplets, which will remain in the water column to be naturally biodegraded. When gas is present as was the case in the Deepwater Horizon incident where it was estimated that the plume consisted of ~22% natural gas, the LISST cannot distinguish between oil droplets and gas bubbles and thus is not able to track the effectiveness of dispersants in the presence of gas. Acoustic measurements overcome the problems associated with the LISST and fluorometers and are ideal for applications subsurface near a blowout and for low ppm levels expected for surface slicks. One of the key features of the sound wave propagating through the water is the scattering at the interface between the water and object. In previous work we showed the proof of concept to measure the average oil droplet size using acoustic. We used the resonance behavior of the gas bubbles to identify them and separate their contribution to the measured acoustic scattering for various oil and dispersant combinations . We developed acoustic scattering and resonance measurements to track the size of oil droplets in the presence of gas during subsurface releases at SINTEF and in Ohmsett's large wave tank.

Anti-Deposition Agents to prevent Spilled Oil from Fouling the Coastal Environment and Ecology

Following the recent Deepwater Horizon incident in the Gulf of Mexico, more than one million gallons of dispersant was deployed to the site of the spilled oil. The clean-up strategy in this case was to keep the oil at sea until it was microbiologically degraded. However, in many cases, such as near shore and inland water spills, conventional dispersants cannot be deployed. There is a need for oil treatments that prevent or at least minimize the wetting and spreading of oil on solid substrates, animate and inanimate. In response to the Deepwater incident, we devised anti-depositing dispersants to mitigate the deposition of oil on solid coastal surfaces including soil, sand, plants, and wild-life (especially birds). We focused on materials that were GRAS for human consumption by using commercially-available food-grade materials to provide an economical and environmentally friendly option for oil spill treatment. The dispersant comprises a primary surfactant, soy lecithin, which is biodegradable in the marine environment, and certain cellulose ethers as steric stabilizers to prevent deposition of oil at the oil/water/solid interfaces. Our technology is set apart from others on the market as it accomplishes all of the following functions:Disperses the oil into small dropletsEncapsulates the dispersed oil dropletsProvides buoyancy to the encapsulated droplets to cause them to move out of the water column to the surface to permit removal by skimming or other conventional meansInherently contains nutrients to initiate microbial biodegradation of the encapsulated oilConfers anti-deposition properties to prevent fouling and penetration of coastal substrates (such as birds and sediment) for the oils that escape capture by skimming and absorption.Comprises natural, renewable, environmentally-friendly, edible componentsAbstract classification: #5: Chemical Response Agents (other than dispersants)

High sensitivity liquid chromatography tandem mass spectrometric methods for the analysis of dioctyl sulfosuccinate in different stages of an oil spill response monitoring effort

After the incident on the Deepwater Horizon platform, around 1.8 million gallons of dispersants were used in the field as part of the response cleanup efforts. This study describes an online solid phase extraction-liquid chromatography (LC)-tandem mass spectrometry (MS/MS) method and a direct-injection LC-MS/MS method for the analysis of dioctyl sulfosuccinate (DOSS; a component in Corexit® EC9500A) in seawater at trace levels, with method detection limits (MDLs) of 7.0 and 440 ng/L and run times of 7 and 17 min, respectively. Stability and preservation studies demonstrated that samples at 4.7 μg/L could be preserved for up to 150 days without loss of analyte when stored with 33 % acetonitrile in glass containers. Data acquisition was performed by heated electrospray ionization (ESI) MS/MS operating in negative mode. Methods were validated in terms of percent recovery in fortified blank and matrix samples and to evaluate carryover. A simple modification of the direct-injection method allowed quantitation of 2-butoxyethanol, a dispersant component specific to the Corexit® EC9527A formulation. This method was used to simultaneously quantify DOSS and 2-butoxyethanol in two Corexit® formulations and extracts from an MC-252 source oil standard. MDLs in crude oil were 0.723 and 4.46 mg/kg, respectively, with recoveries of (92 ± 9)% for DOSS and (104 ± 8)% for 2-butoxyethanol. Detection of both indicators was achieved in a single chromatographic run by ESI-MS/MS operating sequentially in positive and negative mode. Corexit® EC9500A and Corexit® EC9527A were found to contain (21 ± 2)% and (22 ± 5)% w/w DOSS and 0 and (37 ± 2)% w/w 2-butoxyethanol, respectively.

Impact of the Deepwater Horizon Oil Spill on Bioavailable Polycyclic Aromatic Hydrocarbons in Gulf of Mexico Coastal Waters

An estimated 4.1 million barrels of oil and 2.1 million gallons of dispersants were released into the Gulf of Mexico during the Deepwater Horizon oil spill. There is a continued need for information about the impacts and long-term effects of the disaster on the Gulf of Mexico. The objectives of this study were to assess bioavailable polycyclic aromatic hydrocarbons (PAHs) in the coastal waters of four Gulf Coast states that were impacted by the spill. For over a year, beginning in May 2010, passive sampling devices were used to monitor the bioavailable concentration of PAHs. Prior to shoreline oiling, baseline data were obtained at all the study sites, allowing for direct before and after comparisons of PAH contamination. Significant increases in bioavailable PAHs were seen following the oil spill, however, preoiling levels were observed at all sites by March 2011. A return to elevated PAH concentrations, accompanied by a chemical fingerprint similar to that observed while the site was being impacted by the spill, was observed in Alabama in summer 2011. Chemical forensic modeling demonstrated that elevated PAH concentrations are associated with distinctive chemical profiles.

Tracking the Dispersant Applied during the MC252 Deepwater Horizon Incident

Abstract As part of the response strategy, dispersant was applied to oil from the MC252 Deepwater Horizon both at the surface and at the well head. Around 90% of the dispersant used was Corexit EC9500A, with a small amount of Corexit 9527 used during the initial stages of the response. In total, around 1.8 million gallons of dispersants were applied. The purpose of the dispersant was as follows: Remove oil from the surface and enhance its microbial degradation within the water column Reduce airborne concentrations of volatile organic compounds (VOCs) around the source site Reduce the amounts of oil ultimately reaching the shoreline. Corexit EC9500A contains several surface active agents in a solvent package; all of the components are individually used in other formulations in cosmetics, medicines, or cleaning products. This report focuses on one of these, dipropylene glycol n-butyl ether (DPnB), a component of the solvent package with weak surfactant properties itself. Corexit EC9500A contains two isomers...

Oil and Water

Oil and Water

OIL SPILL INCIDENTS AND DISPERSANT APPLICATIONS IN KUWAIT

ABSTRACT Since the discovery of oil in Kuwait, most oil-related activities have been located along the coastline 50 km south of Kuwait City. Other related industrial activities have been developed in this area apart from oil and petroleum products export in order to diversify the national sources of income. For these reasons, the potential for large oil spills in Kuwait's marine environment is highest along the south coast, where oil refineries and exporting facilities are located. An average of 219 barrels of oil were spilled annually between 1979 and 1985, and 2,100 gallons of dispersants were used in cleanup operations. The majority of incidents involved less than 5 barrels of oil and 500 gallons of dispersants. Incidents involving more than 100 barrels of oil and 5,000 gallons of dispersants were confined to the Sea Island and Mina Al-Ahmadi North and South Piers. This distribution undoubtedly affects the concentration of petroleum residues in various components of the marine environment, resulting in an increase in tar ball density along this coast, reaching a maximum at Ras Az-Zor, and significantly higher levels of vanadium and petroleum hydrocarbons in sediments and oysters collected south of Mina Al-Ahmadi. The objective of this paper is to report on the number, volume, and frequency distribution of oil spill incidents in Kuwait and the usage of dispersants in cleanup operations. Vanadium and petroleum hydrocarbon concentrations also are described as is the sensitivity of the southern coastal environment to oil spills. Recommendations have been made on how to conduct cleanup operations for any future oil spill incidents along the southern shoreline of Kuwait.