Phytoremediation
What
is Phytoremediation?
- Phytoremediation is using plants to clean up the environment. The word
Pytoremediation comes from the Greek word phyton, meaning "plant,"
and the Latin word remediare, meaning "to remedy". This word
in general is used to describe any system where plants are introduced into
an environment to remove contaminants from it. This is done in a variety
of ways. The plants can be introduced into an environment and allowed to
absorb contaminates into it's leaves and roots. These plants can then be
harvested and treated as hazardous waste. There have even been studies
where these plants have turned the contaminate into a harmless substance
and then once harvested can be used for mulch, animal feed, paper, etc.
In some instances (especially if trees are being used) the plants are left
in the environment and allowed to grow and mature as normal.
Where
Did Phytoremediation Come From?
- The concept of using plants to clean up their environment is not a
new one, but most research in this area was strictly in studying those
few wild plants that actually grew in waste infested areas. It wasn't until
Dr. Ilya Raskin, a Russian born US educated scientist, came along that
phytoremediation was actually born. Dr. Raskin, who not only came up with
this new technology involving plants, but also named it; came to the United
States in 1976. In 1989, he encountered a company called Envirogen Inc.
which was using mico-organisims to degrade and clean up oils and chemicals
in soil. Dr. Raskin became interested in finding a similar technology to
clean up heavy metals, one this micro-organisms just can't do. It was at
this point that Dr. Raskin remembered some reading he did back home. he
states: "I remembered reading Russian papers from the 1930's and 1940's
about geobotany, in which they prospected for minerals by looking at the
plants. Some plants have a high capability of accumulating metals from
the soil." These plants gave a clue to what minerals were under the
surface, but couldn't these same plants be used to absorb the metals from
the soil? It was then that phytoremediation was born. Dr. Raskin and others
have science spent many hours finding those plants that best took metals
from their environment.
What
Can Phytoremediation be Used For?
- Pytoremediation can and has been used to clean up metals, pesticides,
solvents, explosives, crude oil, polyaromatic hydrocarbons, land fill leachates,
agricultural runoff, acid mine drainage, radioactive contamination, etc.
Why
Use Phytoremediation?
- Phytoremediation is an environmentally friendly, safe, cheap way to
clean up contaminants. Early estimates on the costs have shown that plants
could do that same job as a group of engineers for one tenth of the cost.
The plants are also more pleasing to look at than many such operations
are. The soil or water need not be gathered in and stored as hazardous
waste, requiring large amounts of land, money, and man power. Plants can
be planted, watered, and then harvested with less man power. If need be
the storage of the harvested plants as hazardous waste would be a far smaller
amount. The main drawback on the use of technology is that it isn't good
for all sites. If the contamination runs too deep, or is too much the plants
alone can't handle it. Studies have been done though where the ground water
is pumped out and then treated.
Why
Phytoremediation For the
Tuba City UMTRA Site?
- I propose using phytoremediation as a safer and more culturally fitting
remediation for the Tuba City site. The water which we want to clean up
has been contaminated with Uranium, but water is very important to the
people of this area. Water is very important culturally to both the Navajos
and the Hopi. Using water hyacinth to clean the water would allow the water
to be cleaned and then used. The water could be pumped out of the ground
with pumps that are already in place, and then held in the retaining ponds
which have already been built while the water is being treated.
Return to Phytoremediation
and the Tuba City UMTRA Site