The Oil Drum: Canada | Tar Sands: The Oil Junkie's Last Fix, Part 2

94 comments on Tar Sands: The Oil Junkie's Last Fix, Part 2

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joule on September 9, 2007 - 12:07pm

The wastewater problem is indeed huge, but it doesn't have to be as bad as it currently is. I would probably be correct in surmising that the composition of this wastewater is not unlike a combination of petroleum refining effluent and coal process wastewater.

As such, a variety of conventional wastewater treatment technologies could be applied to greatly improve the quality of this effluent. Coagulation and seettling followed by metals precipitation, sand filtration, and then some form of biological treatment, with perhaps a carbon adsorption 'polishing' step would probably effect at least a 97% removal of most the various chemical constituents.

Given the large volume of wastewater generated, such a treatment system would not be cheap, but it is technically doable. I am a bit surprised (though perhaps I shouldn't be) that the Canadian government didn't require some form of wastewater treatment to be in place even before the whole thing went into operation. In any event, some form of treatment is inevitable, as they cannot store this wastewater in ponds forever. And the longer they wait, the harder it is going to be, because they will not only have to treat the new wastewater as it is being generated, but also will have to work off the huge inventory of old wastewater accumulated in those ponds.

Even if a treatment system is 99% effective, the absolute pollutant loading in terms of lbs per day of the various chemical constituents will still be large and will still represent a considerable negative environmental impact on whatever receiving stream it is discharged to.

While they can make it not as bad, but they can never make it good.

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dragonfly on September 9, 2007 - 1:30pm

Hello everybody. Has anyone seen evidence that the oil industry invests anything at all in order to pilot test and foster development of the technologies they need in order to solve the crucial water problem? I somehow doubt that this is an active area of industry investment. If a technology were proven, then the industry would experience pressure to actually use it. Without adequate technology, it is easier to make the argument to simply release the polluted water back into the rivers, or to create huge artificial lakes full of polluted water

Below is a reference to an article on research done by Sandia National Laboratories, on the bench scale, on a technology, called capacitive deionizatsion, to handle a similiar water problem, produced water from Coal Bed Methane. Worthwhile technologies like this are well documented to exist, but have received insufficient pilot testing. Competent due diligence has also been lacking. To date, the state of New Mexico paid for a small pilot to test this particular technology for arsenic remediation.

http://pubs.acs.org/subscribe/journals/esthag/40/i03/html/020106tech.html

Sandia's website on this new technology, called capacitive deionization, may be found at

http://www.sandia.gov/water/desal/research-dev/alternative-tech.html

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joule on September 9, 2007 - 3:40pm

dragonfly -

As a (retired) environmental engineer, I would have to say that treating the wastewater from tar sand operations to an acceptable level does not require any exotic new technology, but rather the application of existing best available treatment technology, based thorough pilot testing and good engineering design.

The problem, of course, is that currently nobody is making them do anything other than hold the wastewater in giant earthen impoundments. As I said, this practice cannot go on forever, and eventually some form of treatment will be required. The situation reminds me of US industry in the early 1970s: if a gun was not held to their heads to install pollution control systems, it just wouldn't happen.

I suspect that the area where some real innovation can be applied is treated wastewater recycle. I don't know enough about the tar sand process to be specific, but I would think that for some of the operations water quality is not that critical and might be successfully served by (partially) recycled wastewater. As water availability appears to be one of the limiting factors in Alberta tar sand operations, I would think that there should be a strong incentive to explore wastewater recycle possibilities.

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dragonfly on September 9, 2007 - 4:38pm

Thank you for the comment. One would think that what you say is true, that there would be a strong incentive to explore waste water recycle opportunities. Howevr, I don't see much evidence that industry has agressively or even non agressively, pursued opportunities to innovate here.

A key technical concern when recycling waste water is the rapid build up of salinity, removal of which becomes the limiting step. Therefore, not only does salinity ( and "t.d.s.", total dissolved solids) need to be removed, but it needs to be done with high water recovery, in order to maintain the aim of saving water. Technologies that treat t.d.s are few, and tend to be older than the alphabet. Use of any existing technologies in order to achieve high recoveries with produced water, which is likely to have compounds that would tend to foul water treatment systems, would in and of itself be an experiment.
Therefore, any technology would be a new technology when used under these conditions. Some of the older technologies, such as R.O ,have been tested to death., while promising new technologies have received insufficient or incompetent due diligence

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joule on September 9, 2007 - 7:25pm

Generally, salinity build-up only becomes a problem when one goes to very 'tight' recycle systems.

I would venture that if the tar sands process can use recycled wastewater at all, it would probably be able to tolerate at least a 75 percent recycle rate, which would reduce net water consumption by a factor of about four.

However, once one tries to tighten up the wastewater recycle much beyond that point, various problems with salinity, corrosion, scaling, bio deposits, etc. can rear their ugly head.

I think that given the critical water supply situation in the Alberta tar sands, wastewater recycle is an area well worth exploring.

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Dryki on September 9, 2007 - 8:53pm

It will never be cleaned up. What the businesses are doing is stockpiling the waste in holding ponds and piles; when the bonanza is over, they will claim they don't have the money to clean it up and/or go belly up and dissolve.

cfm in Gray, ME

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