Phytoremediation

[whitewind]

Phytoremediation

Restoring the balance of the environment, by treating environmental pollutants in the soil / air using plants to alter the balance of constituents.

This article at The Guardian prompted me to post a thread about Phytoremediation using plants, to see if anyone had any knowledge / experience of working with plants. Recently I was working with someone from the US who was doing a study on Nickel extraction using an Aussie native (which hasn't been published yet, so I'm not sure if I can mention details yet – will check).

In the press, carbon dioxide sequesteration is a big topic as it is a relatively simple method of binding carbon into the soil, can be done by all plants and is arguably essential to avoid long-term climate change but the type of plants being grown and the methods used tend to ensure that a net effect is that more CO2 is emitted than carbon sequestered. There are some studies that suggest certain plants (like bamboo, for example) sequester carbon much more quickly than your average tree, but monoculture agriculture definitely has a releasing impact.

Bamboo has also been used as to help treat sewerage, having better results when the more wet-tolerant species are used.

Here is a small list of plants used, as shown in this Wikipedia entry.

Arsenic, using the Sunflower (Helianthus annuus), or the Chinese Brake fern (Pteris vittata), a hyperaccumulator. Chinese Brake fern stores arsenic in its leaves.

Cadmium, using willow (Salix viminalis): In 1999, one research experiment performed by Maria Greger and Tommy Landberg suggested willow has a significant potential as a phytoextractor of Cadmium (Cd), Zinc (Zn), and Copper (Cu), as willow has some specific characteristics like high transport capacity of heavy metals from root to shoot and huge amount of biomass production; can be used also for production of bio energy in the biomass energy power plant.

Cadmium and zinc, using Alpine pennycress (Thlaspi caerulescens), a hyperaccumulator of these metals at levels that would be toxic to many plants. On the other hand, the presence of copper seems to impair its growth (see table for reference).

Lead, using Indian Mustard (Brassica juncea), Ragweed (Ambrosia artemisiifolia), Hemp Dogbane (Apocynum cannabinum), or Poplar trees, which sequester lead in their biomass.

Salt-tolerant (moderately halophytic) barley and/or sugar beets are commonly used for the extraction of sodium chloride (common salt) to reclaim fields that were previously flooded by sea water.

Caesium-137 and strontium-90 were removed from a pond using sunflowers after the Chernobyl accident.

Mercury, selenium and organic pollutants such as polychlorinated biphenyls (PCBs) have been removed from soils by transgenic plants containing genes for bacterial enzymes.

So, does anyone know anything about using Australian natives or any other plants to help remediate environmental pollution?

[waterboy 2.0]

What do you want to know WW, I've used plants professionally in several roles. Also use rhizosphere associations for particularly hydrocarbon rehab.

If you send me your email I can send you a little gem called "Vegetation useful for environmental engineering" that was put together by DPIW down here I have one of three copies I know of and have it ghetto scanned.

Also another primer is to to look into Water Sensitive Urban Design(WSUD) . Tas,QLD and Melbourne have manuals with useful lists of natives suitable for their climates for hydrocarbon, metals etc. Bioinfiltration basins may be a concept that will interest you.....

EDIT - re the nickel it isn't an accumulation within a viola ssp by chance

Edited February 21, 2013 by waterboy

[briliant_botanist]

I know of a study which had been undertaken in the river land in SA using salt bush to rejuvenate fields that had been over worked over many years & after one year cycle of growing salt bush the fields had been restored to within 95% of original consistency & ready to farm again with regular cropping & so forth!