techniques to "clean" soil contaminated with diesel fuel 4

[georam]

Could anyone suggest the techniques to remediate soil which has been contaminated with diesel fuel ? Any chemical mixes which can be added to "neutralize" or remove the fuel from the soil. Bioremediation techniques ? If aeration/exposing to open air and turning it over a couple of times, how long will it take to actually clean this soil.... months or years? The soil is relatively granular, and consisting of reddish brown shale particles.
Thanks for info

 

[RMCNORTHEAST]

I am not an expert on this subject but I have designed a hundred or so gas stations. You did not say whether the soil was in the ground or dug out and stockpiled. I will assume for the sake of this reply that the soil is stockpiled on site and not a huge quanity. Aeration would probably take a considerable amount of time as diesel does not evaporate quickly. I do not know the state you are in but you could consider burning it. There are companies (depending on regulations) that take the soil and run it through a large portable oven the burns off the fuel in the soil. You need to check and see if your area allows it and the permits that are required. It works fairly quickly on small amounts but can be somewhat expensive. Also, protection must be provided as the soil needs time to cool down.

 

[vintage70]

A very economical treatment method would be asphalt batching. Soil contaminated with diesel or fuel oil is mixed as part of the aggregate with the asphalt. Cost is approx. $65 to 75$ per ton.

 

[Dubliner]

Hi Georam. There are a few options open to you here, mostly dependant upon the amount of fluid spilled, remediation time available, geology/hydrogeology/hydrology and whether or not remediation takes place in situ.
If there is a pathway from the contaminated soil down to an aquifer, and that aquifer is used by someone or contributes to the flow of a river then the soil will probably need cleaning.
Bio-remediation of diesel is possible and can be encouraged by injecting food for the micobes, maybe controlling temperature and ensuring aerobic/anaerobic conditions (depending upon the needs of the microbial colony). As a rough time-guide a cube of soil 20m x 20m x 20m contaminated by DISSOLVED phase diesel might be bioremediated in 6 months (with food and oxygen added). If FREE PHASE diesel is still present then much more time would be required (x2, x3 or more depending upon the amount of liquid diesel present).
In situ cleaning of the soil could be done by air-sparging and soil vapour extraction (SVE). Air is pumped down via input boreholes and a vacuum is applied to other output boreholes. The idea is that the vapour phase of the (volatile) diesel flows from the areas around the inputs and on towards the outputs where it is removed, which either allows more free-phase diesel to evaporate or dissolved diesel to come out of solution.
Ex-situ remediaiton would involve removing the contaminated soil and having it either landfilled (very expensive), soil washed (expensive) or treated off-site. Uncontaminated soil could be purchased and brought to the site if time is at a premium.
I hope this all makes sense, feel free to let me know if you need clarification or further information.
Adam Beresford-Browne, Hydrogeologist, URS Dames & Moore (Dublin)

 

[TAC]

The site our new office is built on is a browfield site that is contaminated with deisel fuel. We are cleaning the site using vapor extraction below the building pad and are experimenting with more passive methods as well. We have planted a group of hybrid poplar trees on one side of the building. The trees were placed in augered holes so that the roots would take in the contaminated soil layer. The contaminants are absorbed through the roots and evavaporated through the leaves. On the back side of the building, we planted prarie grasses which tend to grow deep roots that will penetrate into the contaminated layer. The building was built about 2 years ago and we have seen improvement, but its not clean yet. If you would like more specific information, let me know and I will put you in contact with the person involved in the project.

 

i would like to write a report on slope stability..
a proposed hotel is going to be built in a sloped surface(hill) so my task is to examine the problems that may occur to this situation..
any ideas please??
i would really appreciate it
thanks in advance

 

I am the Archaeologist for Marine Corps Bases, Japan. We currently have a site that we are excavating for site clearance and development. Construction of the new facility depends on getting the archaeological site clearance. We have discovered diesel fuel from an old UST on the site and the contractor will not do any further excavation until the site has been cleaned up. I have proposed to dig four trenches removing the contaminated soil and bioremediate using Micro Blaze. We have been experimenting with Micro Blaze with some success, but this will be the first large scale project using it. Does anyone have any comments or suggestions on my dilemma, I have a three star general breathing down my neck. Thanks.

 

[Dubliner]

Gusuku

From the pace of your message it seems that time is of the essence here and you have to act quickly. I suggest you subcontract the job to an environmental consultancy and get them to arrange for the removal of the offending soil and UST. There may be a local treatment facility available or you may have to have it shipped abroad. To give you an idea, local treatment costs around IR£100/tonne in Ireland.
In situ bioremediation (Micro Blaze) would not seem to be an option for you unless you can convince your general that you need 3-6 months before you can continue working (how much contaminated soil is there? a few cubic metres? a few hundred?).
URS Dames & Moore have offices in Shanghai, Jakarta, Singapore and Manila. One of these offices may be able to offer some more appropriate advice.
I wish you good luck with this.

Adam B-Browne
URS Dames & Moore, Dublin, Ireland.
+353 1475 4422

 

Thanks Dubliner. Time is of essence here, and it is growing shorter. We have pretty extensive contamination (a few hundred cubic meters), and need to do something fast. I have worked with Dames & Moore before and may look into that as an option. The problem being with the local government is that we have to proceed slowly with digging the soil out and document any cultural artifacts and features along the way.

 

[Dubliner]

Well Gusuku, I hope things work out for you!

Ganbatte!

 

[Muggle]

Same note here as the oil spill in the basement. You can inject specific catalytic enzymes into the soil to "remediate/remove" diesel and gasoline. Very simple process, and not expensive. You can speed the process by mixing enzymes with a microbial mix, does not matter if anaerobic or aerobic microbes. We have used this for years to clean up ground contaminated from leaking fuel storage tanks - and leach fields for RV parks, etc. where folks are always dumping car oil and other hydro-carbons down the flush lines.

Contact Dick Kersey at Orenda Technologies - 800-322-1648. Good guy and knows his stuff.

Dave Orlebeke/Aquatic Technologies

 

[KRSServices]

I have had a couple of instances where soil had to be spread and disked to provide aeration. The length of time depended on the concentration of the BTEX compounds. One was a year, the other is going on two now. However, once aerated, the soils become perfect for intermediate cover in landfills. That is where some of the "produced sand" from heavy oil extraction. The rest is blended to form an engineered "coldmix" and hauled to caverns. Kinda off topic, but the soil can be utilized, particularly if it is granular. KRS Services

http://www.krs-services.com

 

[Isadore]

We have found at several on site piles of contaminated soil (diesel) that the addition of Nitrate in warm temperatures (turning the soil over periodically) has a marked affect on the accelerated oxidation of the hydrocarbons. Now, there might be a state or local ordinance which might have something to say about this technique, you'd have to check, but the results are quite good.

 

[Dubliner]

These last two posts, although helpful, do not point out that the oxidation of hydrocarbon contamination is microbiologically controlled, the addition of electron donors, fuel or warmth merely enhancing the process. In the absence of life these additions would do little (if anything) to break down the hydrocarbons.

Sorry if I am being pedantic but I thought it worth pointing out.

As I said before, in-situ remediation is but one of many solutions to the problem of dealing with contaminated soil. I am focussing on larger cases of contamination here, with free-phase product in the ground. If groundwater is shallow and there are free-phase hydrocarbons floating on the water table then you can be sure that hydrocarbons are dissolving into the aquifer and treating the soil will only remove part of the problem. Bear in mind that contaminated groundwater can contaminate clean soils - digging out filthy soil and replacing it with clean will only work if the groundwater doesn't then return to it's level and bring more contamination with it.

Respectfully yours,

Adam Beresford-Browne
Hydrogeologist
URS Corporation Ltd, Cardiff, UK