Phytoremediation describes the treatment of environmental problems (bioremediation) through the use of plants. Devils Punchbowl Waterfall, New Zealand. ... Bioremediation can be defined as any process that uses microorganisms or their enzymes to return the environment altered by contaminants to its original condition. ... Divisions Land plants (embryophytes) Non-vascular plants (bryophytes) Marchantiophyta - liverworts Anthocerotophyta - hornworts Bryophyta - mosses Vascular plants (tracheophytes) Lycopodiophyta - clubmosses Equisetophyta - horsetails Pteridophyta - true ferns Psilotophyta - whisk ferns Ophioglossophyta - adderstongues Seed plants (spermatophytes) †Pteridospermatophyta - seed ferns Pinophyta - conifers Cycadophyta - cycads Ginkgophyta - ginkgo Gnetophyta - gnetae Magnoliophyta - flowering plants Adiantum pedatum (a fern...

The term phytoremediation describes a range of processes mediated by plants that are useful in treating environmental problems:

• Phytoextraction - uptake and concentration of substances from the environment into plant biomass.
• Phytostabilization - reducing the mobility of substances in the environment, for example by limiting the leaching of substances from the soil.
• Phytotransformation - chemical modification of environmental substances as a direct result of plant metabolism, often resulting in their inactivation, degradation (phytodegradation) or immobilization.
• Phytostimulation - enhancement of soil microbial activity for the degradation of contaminants, typically by organisms that associate with roots. This process is also known as rhizosphere degradation.
• Phytovolatilization - removal of substances from soil or water with release into the air, sometimes as a result of phytotransformation to more volatile substances.
• Rhizofiltration - filtering water through a mass of roots to remove toxic substances or excess nutrients.

Phytoremediation describes the treatment of environmental problems (bioremediation) through the use of plants. ... To meet Wikipedias quality standards, this article or section may require cleanup. ... Leaching is the process of extracting a substance from a solid by dissolving it in a liquid. ... Soil is material capable of supporting plant life. ... Phytoremediation describes the treatment of environmental problems (bioremediation) through the use of plants. ... Santorio Santorio (1561-1636) in his steelyard balance, from Ars de statica medecina, first published 1614 Metabolism (from μεταβολισμος (metabolismos)) is the biochemical modification of chemical compounds in living organisms anggjgjhnd cell (b). ... Soil life is a collective term for all the organisms living within the soil. ... Primary and secondary roots in a cotton plant In vascular plants, the root is that organ of a plant body that typically lies below the surface of the soil (compare with stem). ... Rhizosphere, the zone that surrounds the roots of plants. ... Nutrients and the body A nutrient is any element or compound necessary for or contributing to an organisms metabolism, growth, or other functioning. ...

Phytoextraction

Phytoextraction (or phytoaccumulation) uses plants to remove contaminants from soils, sediments or water into harvestable plant biomass. Phytoextraction is growing rapidly in popularity world-wide. Generally this process has been more effective for extracting heavy metals than organics. It is clean, efficient, inexpensive and less environmentally desruptive than processes that require excavation of soil. At the time of disposal contaminants are typically concentrated in a much smaller volume of plant matter than an inital contaminated soil or sediment.

After the plant absorbs contaminants through the root system it will either store them in the root biomass or transport them up into the stems and leaves. A living plant may continue to absorb contaminants until it is harvested. After harvest a lower level of the contaminant will remain in the soil, so the growth/harvest cycle must be repeated through several crops to achieve a significant cleanup. After the process, the soil usually is fertile and can support other vegetation.

There are two versions of phytoextraction:

• natural hyper-accumulation, where plants naturally take up the contaminants in soil unassisted, and
• induced or assisted hyper-accumulation, in which a conditioning fluid containing a chelator or another agent is added to soil to increase metal solubility or mobilization so that the plants can absorb them more easily.

Examples of Phytoextraction from Soils:

• Lead, using Indian Mustard, Ragweed or Hemp Dogbane.
• Arsenic, using the Sunflower (Helianthus annuus), or the bracken fern, a hyperaccumulator. Bracken can store arsenic in its leaves, as much as 200 times that present in the soil.
• Cadmium and zinc, using alpine pennycress (Brassicaceae), a hyperaccumulator of these metals at levels that would be toxic to many plants.
• Uranium, using sunflowers, as used after the Chernobyl accident.

General Name, Symbol, Number lead, Pb, 82 Chemical series poor metals Group, Period, Block 14, 6, p Appearance bluish white Atomic mass 207. ... General Name, Symbol, Number arsenic, As, 33 Chemical series metalloids Group, Period, Block 15, 4, p Appearance metallic gray Atomic mass 74. ... Species Pteridium aquilinum Pteridium caudatum Pteridium latiusculum and about 7-8 other species Brackens (Pteridium) are a genus of about ten species of large, coarse ferns, in the family Hypolepidaceae. ... Classes Marattiopsida Osmundopsida Gleicheniopsida Pteridopsida A fern, or pteridophyte, is any one of a group of about 20,000 species of plants classified in the Division Pteridophyta, formerly known as Filicophyta. ... Phytoremediation describes the treatment of environmental problems (bioremediation) through the use of plants. ... General Name, Symbol, Number arsenic, As, 33 Chemical series metalloids Group, Period, Block 15, 4, p Appearance metallic gray Atomic mass 74. ... In botany, a leaf is an above-ground plant organ specialized for photosynthesis. ... General Name, Symbol, Number cadmium, Cd, 48 Chemical series transition metals Group, Period, Block 12, 5, d Appearance silvery gray metallic Atomic mass 112. ... General Name, Symbol, Number zinc, Zn, 30 Chemical series transition metals Group, Period, Block 12, 4, d Appearance bluish pale gray Atomic mass 65. ... Binomial name Thlaspi caerulescens L. Alpine Pennycress (Thlaspi caerulescens), also known as Alpine Pennygrass, is a flowering plant in the family Brassicaceae. ... Genera See text. ... Phytoremediation describes the treatment of environmental problems (bioremediation) through the use of plants. ... To meet Wikipedias quality standards, this article or section may require cleanup. ... General Name, Symbol, Number uranium, U, 92 Chemical series actinides Group, Period, Block n/a, 7, f Appearance silvery gray metallic; corrodes to a spalling black oxide coat in air Atomic mass 238. ... Binomial name Helianthus annuus L. The sunflower (Helianthus annuus) is an annual plant in the Family Asteraceae with a large flower head (inflorescence). ... The nuclear power plant at Chernobyl prior to the completion of the sarcophagus. ...

Phytotransformation

In the case of organic pollutants, such as pesticides, explosives and industrial chemicals, certain plants render these substances non-toxic by their metabolism.

The Role of Genetics

Breeding programs and genetic engineering are powerful methods for enhancing natural phytoremediation capabilities of plants, or for introducing these tendencies into alternative types of plants which might be more suitable for the environmental conditions. An iconic image of genetic engineering; this 1986 autoluminograph of a glowing transgenic tobacco plant bearing the luciferase gene of the firefly strikingly demonstrates the power and potential of genetic manipulation. ...

See also

• Biodegradation
• Bioremediation
• John Todd - cofounder of the New Alchemy Institute

Biodegradation is the decomposition of organic material by microorganisms. ... Bioremediation can be defined as any process that uses microorganisms or their enzymes to return the environment altered by contaminants to its original condition. ... Dr. John Todd (1939- ) is an important biologist working in the field of ecological design. ...

External links

• International Journal of Phytoremediation - devoted to the publication of current laboratory and field research describing the use of plant systems to remediate contaminated environments.
• Using Plants To Clean Up Soils - from Agricultural Research magazine
• Phytoremediation website hosted by the Missouri Botanical Garden - Review Articles, Conferences, Phytoremediation Links, Research Sponsors, Books and Journals, and Recent Research.

Bibliography

“Phytoremediation Website” - Includes reviews, conference announcements, lists of companies doing phytoremediation, and bibliographies.

“An Overview of Phytoremediation of Lead and Mercury” June 6th 2000. The Hazardous Waste Clean-Up Information Web Site.

“Enhanced phytoextraction of arsenic from contaminated soil using sunflower” September 22nd 2004. U.S. Environmental Protection Agency.

“Getting the lead out”, June 1995. Vegetarian Times.

“Phytoextraction”, February 2000. Brookhaven National Laboratory 2000.

“Phytoextraction of Metals from Contaminated Soil” April 18th, 2001. M.M. Lasat

July 2002. Donald Bren School of Environment Science & Management.

“Phytoremediation” October 1997. Department of Civil Environmental Engineering.

“Phytoremediation” June 2001, Todd Zynda.

“Phytoremediation of Lead in Residential Soils in Dorchester, MA” May, 2002. Amy Donovan Palmer, Boston Public Health Commission.

“Technology Profile: Phytoextraction” 1997. Environmental Business Association.

“The role of EDTA in lead transport and accumulation by Indian mustard” June 1998.