Soil remediation

[lemit]

For practical as well as educational reasons, I'd like to know what kinds of plants can be used to remediate toxic soil.

We locally have a community center built on ground that was a dump for the byproduct of coal gasification for many years. I have volunteered to take on the job of restoring the soil by natural means, using primarily grasses.

Someone who promised to give me technical assistance has vanished. Before I contact the local university range science people (a scurvy lot anyway), I'd like to get some suggestions here.

Any help?

--lemit

[Munin]

There are some folks in the ag school who do some work in phytoremediation here at Purdue. I don't remember who off hand.

[Essay]

Originally Posted by lemit

...to remediate toxic soil.

"Omnivore's Dilemma" Author Michael Pollan's New Advice on Buying Food: "Don't Buy Any Food You've Ever Seen Advertised"
...speaking of toxic soil....

Originally Posted by DemocracyNow!

...countries like China realize that they will not be able to feed their population on their soil base, because of their numbers, but also because they poison so much of their soil.

Gotta run, ...but more power to ya'.
...maybe later I can look for some relevant links, but until then....
===

I was sure happy to hear Michael Pollan (on DemocracyNow! May 14, 2009) say:
[my transcription]

Originally Posted by Pollan

"There is a growing recognition that the great unrenewable resource is arable soil, in this world."

Thankfully, people are beginning to see how rich, healthy soil should be viewed as a valuable commodity.
Certainly it should be more valuable than a financial instrument.

Pollan characterizes "arable soil" as "unrenewable" if I heard him correctly--and I'm sure that could be debated on technical grounds--but the reality is that we do only rarely regenerate our soil. It is even more rare that we grow new soil, and most common that we deplete and wash away our soil--wasting this necessary resource.

...and of course this is not only an important part of fixing our economic system (focusing more on reality--less on derivatives), but as Michael goes on to point out:

Originally Posted by Pollan

"You are not going to be able to tackle either the Health Care crisis or Climate Change, unless you look at our food system."

"It [our agricultural philosophy] is really the shadow issue over these other two issues [health care & climate change]."

[Nitack]

YouTube - Greening the Desert

Perhaps not detoxification, but it speaks to what Essay was posting about.

Additionally, Soil detoxification - Soil Forum - GardenWeb

Sunflowers and mustard greens both have an ability to pull certain toxins (primarily heavy metals) from the soil and have been used in various phytoremediation projects, most notably in New Orleans, cleaning up after Katrina. According to the literature, the greens are not edible but the seeds of the sunflowers are - the toxins are apparently accumulated and stored in the roots and leafy growth but not in the seeds. Other plants that are known to have similar characteristics are spinach, corn, carrots, peas, Commelina communis (dayflower), brake fern and lamb's quarters - brake fern (Pteris vittata) has been widely used for this purpose.

Here is a link that might be useful: plants & soil remediation

Sunflower - Wikipedia, the free encyclopedia

Sunflowers may also be used to extract toxic ingredients from soil, such as lead, arsenic and uranium. They were used to remove uranium, cesium-137, and strontium-90 from soil after the Chernobyl accident (see phytoremediation).

Brassica juncea - Wikipedia, the free encyclopedia

This plant is used to remove heavy metals from the soil in hazardous waste sites because it has a higher tolerance for these substances and stores the heavy metals in its cells. The plant is then harvested and disposed of properly. This method is easier and less expensive than traditional methods for the removal of heavy metals.It also prevents erosion of soil from these sites preventing further contamination.

Pteris - Wikipedia, the free encyclopedia

Pteris vittata (commonly known as brake fern) was discovered to have the ability to "hyperaccumulate" (absorb large amounts of) arsenic from soil. The discovery was somewhat accidental, as the fern was growing at a central Florida site contaminated with large amounts of copper arsenate in the soil. Dr. Lena Q. Ma of the University of Florida later discovered that it had hyperaccumulated considerable amounts of arsenic from the soil. The discovery may lead to the use of pteris vittata as a potential bioremediation plant.

Coal gasification leaves behind plenty of nasty stuff, so you may need a couple of harvests in order to fully detox the soil. Although, that leads to another concern which is disposal of the plant materials. They are in no way suitable for eating or even as house plants due to the large levels of contaminants the plant cells will contain. Additionally, they can not responsibly just be dumped some where else as when they decompose those contaminants will just be deposited where the plants decompose. I'm not sure who would be the proper agency to contact about that.

[Nitack]

List of hyperaccumulators - Wikipedia, the free encyclopedia

Nice list that explains which plants are good for which elements the soil is contaminated with.

[freeztar]

From what I've seen, the type of plant used depends on the contamination.
Do you know what exactly is in the soil?

[lemit]

Originally Posted by freeztar

From what I've seen, the type of plant used depends on the contamination.
Do you know what exactly is in the soil?

The Superfund Brownfields report says coal tar from a coal gasification power was the substance. The site, 15 miles downstream from a "Wild and Scenic" designation on the same river, has also been a city dump, an oil company storage site, and a gas station, according to the preliminary report.

The site still hosts a gas station and a couple oil change places.. The local state representative is going to check the status of the site when the current session is over. For now, let's look at coal tar.

That should be easy. If my memory weren't failing me, I'd almost be able to remember appropriate plants. Lespedeza? Alfalfa? You can plant legumes with almost any grass and the grass will outlive them. But probably, for a recreation center, grasses that will take care of the problem themselves would be better.

I should mention that this site is also 5000 feet high, in the arid American west. And I would like to find either native or apt plants, since that's how the riverbank was planted after the superfund project. I know alfalfa does well here. I have trouble identifying lespedeza, so I don't know how well it does. (Hell, I can't identify a tumbleweed until it hits me in the backside.) There are a lot of grasses that do well here.

Okay. Suggestions?

--lemit

[lemit]

Freeztar,

Since you seem to have some association with the tar family, it seems you would be specially qualified to answer this question.

Am I right about that?

--lemit

[freeztar]

Originally Posted by lemit

The Superfund Brownfields report says coal tar from a coal gasification power was the substance. The site, 15 miles downstream from a "Wild and Scenic" designation on the same river, has also been a city dump, an oil company storage site, and a gas station, according to the preliminary report.

"Coal tar" is pretty ambiguous.

According to the National Psoriasis Foundation and the FDA, coal tar is a valuable, safe and inexpensive treatment option for millions of people with psoriasis and other scalp conditions. [4] Coal tar concentrations between 0.5% and 5% are safe and effective for psoriasis, and no scientific evidence suggests that the coal tar in the concentrations seen in non-prescription treatments is carcinogenic. The NPF states that coal tar contains approximately 10,000 different chemicals, of which only about 50% have been identified [5], and the composition of coal tar varies with its origin and type of coal (eg: lignite, bituminous or anthracite) used to make it.

Coal tar - Wikipedia, the free encyclopedia

So, who knows unless you can get a full report.

If my memory weren't failing me, I'd almost be able to remember appropriate plants. Lespedeza? Alfalfa? You can plant legumes with almost any grass and the grass will outlive them. But probably, for a recreation center, grasses that will take care of the problem themselves would be better.

Lespedeza is a bad word in the Southeast. If it works well out there without being invasive, more power to it. I'm completely unfamiliar with Lespedeza for bioremediation, though it makes sense intuitively. It grows fast and requires very little.

I should mention that this site is also 5000 feet high, in the arid American west. And I would like to find either native or apt plants, since that's how the riverbank was planted after the superfund project.

If this is a superfund site, the soil should have already been restored. Contaminated soil should have been isolated and removed and new uncontaminated soil deposited in its place.

EDIT: What has taken place with this superfund site so far?

[Munin]

Paul Stamets wrote Mycelium Running: How Mushrooms Can Help Save the World a book that talks largely about bio-remediation with fungus. It might be worth a look, though it may be of limited usefulness at an arid site.