To better understand the impact of the Deepwater Horizon (DWH) incident on commercially and ecologically important pelagic fish species, a mahi-mahi spawning program was developed to assess the effect of embryonic exposure to DWH crude oil with particular emphasis on the effects of weathering and dispersant on the magnitude of toxicity. Acute lethality (96 h LC50) ranged from 45.8 (28.4-63.1) μ...

one of the most chemical methods for controlling of oil spills is use of dispersants, which arewidely being used worldwide. in this research, comparison of acute toxicity of crude oil of the persian gulf-khark area (co), iranian naftroob crude oil dispersant (ind), radiagreen osd dispersant crude oil (rd), themixture of crude oil and iranian naftroob dispersant ( co-ind) and crude oil with radi...

During the 2010 Deepwater Horizon oil well blowout in the Northern Gulf of Mexico (GoM), the application of 6.97 million litres of chemical dispersants was used at the well-head and on the sea surface to promote oil degradation and weathering of the Mississippi Canyon 252 (MC252) crude oil. Chemical dispersants encourage microbial degradation by increasing the surface area of the spilled oil, w...

The stability of crude oil droplets formed by adding chemical dispersants can be considerably enhanced by the use of the biopolymer, hydrophobically modified chitosan. Turbidimetric analyses show that emulsions of crude oil in saline water prepared using a combination of the biopolymer and the well-studied chemical dispersant (Corexit 9500A) remain stable for extended periods in comparison to e...

Dispersants are important tools in oil spill response. Taking advantage of the energy in even small waves, they disperse floating oil slicks into tiny droplets (<70 μm) that entrain in the water column and drift apart so that they do not re-agglomerate to re-form a floating slick. The dramatically increased surface area allows microbial access to much more of the oil, and diffusion and dilution...

During the Deepwater Horizon oil well blowout in the Gulf of Mexico, the application of 7 million liters of chemical dispersants aimed to stimulate microbial crude oil degradation by increasing the bioavailability of oil compounds. However, the effects of dispersants on oil biodegradation rates are debated. In laboratory experiments, we simulated environmental conditions comparable to the hydro...

In this research, two series of ultra-low cement high alumina refractory castables containing 0 and 0.4 wt.% of nano-titania were prepared using different amounts of polycarbonic acid (DOLAPIX FF 26) as a dispersant. Several characteristics including microstructure, flowability, mechanical strength, bulk density and apparent porosity of the samples were analyzed. The results showed that the opt...

In the present research, the aqueous suspensions of nano-sized YSZ particles were prepared using a common and available dispersant (Dolapix CE64) at different pH values and their stability were evaluated through the sedimentation height, viscosity measurement, and microstructural observation. Different amounts of dispersant were tested and the optimum percentage was examined by measuring the vi...

We illustrate in this paper the interest of cryo-field-emission gun scanning electron microscopy (cryo-FEGSEM) to investigate the stability of alumina suspensions. The stability is investigated through viscosity, zeta potential, total organic carbon measurements, and cryo-FEGSEM observations. We focus on two examples: the effect of the quantity of ammonium polyacrylate as dispersant and the eff...

The purpose of this study was to evaluate the physical properties and hydration evolution of calcium aluminate cement (CAC) compositions containing an advanced dispersant. The compressive strength, dimensional change, apparent porosity and quantitative X ray diffraction analysis (XRD) of the cement pastes were carried out over 1-15 days of curing (with the samples immersed in distilled water) a...