From left to right:
Vial 1: This vial shows a "water only" shake test control. A tarball was removed from the sample, placed in the test vial, and agitation was applied. Notice that the tarball remained intact and did not release oil. Only loosely held sand from the shell of the tarball was released. Vial 2: A small amount of enzyme/protein solution was added to the water in the second vial. Agitation was performed. As evidenced, the aqueous solution (the water and enzyme/protein solution) changed color, indicating that as the tarball was broken down some portion remained in the solution of whatever dispersants were originally applied by BP to the oil. Further testing will be performed to determine more information regarding the nature of those dispersants. One such dispersant that BP uses which has garnered much media attention is Corexit 9500.
The nature of our aqueous solution is such that the oil is more attracted to it than it is to sand. Further, it changes the character of the oil/dispersant mixture (tarball) so that it no longer will congeal and hold sand. At this stage the sand is mostly clean. Since this was a simple shake test there was insufficient agitation to achieve complete contact between the aqueous solution and the sand/oil which would have provided for more complete cleaning.
Vial 3: In addition to the process performed on Vial 2, we added an emulsion breaker. In commercial operation, the clean sand would have already been removed before applying the emulsion breaker. Accordingly, this step would be performed as part of our liquid/liquid separation process which allows for the recovery of the oil. When BP applied its dispersant to the oil, an emulsion was formed between the dispersant, the oil, and seawater. In Vial 2 this emulsion was still intact which is why the oil was not clearly visible in the solution. The emulsion breaker reverses the effects of whatever dispersant BP applied, breaking the emulsion, and allowing the oil to separate out from the water/dispersant/oil mixture. The results of this are visible in Vial 3 where the layer of crude floating on top of the solution is clearly differentiated.
Vial 4 (jar): Vial 4 was a test of a portion of the generalized sample from which we had selected the tar balls for the previous tests. The same percentage aqueous solution was applied. A hand mixer was used which allowed for greater agitation than in the previous tests. This provided sufficient sheer and particular contact resulting in a more complete cleaning of the sand than in the previous tests. The emulsion breaker was not applied because the sand has not yet been separated out. Stay tuned for follow up photos and videos which will show the separation of the cleaned sand from the solution.
