Vetiver Phytoremediation Technology at work! Watts Bridge, Australia. |
Did you see the recent article in The Washington Post “Chinese official: Soil pollution hurts
farming” claiming that at
least 8 million acres of Chinese farm land will be closed to production due to
contamination by heavy metals and other contaminants, including the over use of
agricultural chemicals? This problem is
not just confined to China. In India
ground water is not only being depleted at an alarming rate, but it is also
being polluted by overuse of agricultural chemicals and by toxic effluent from
industry. “A recent Punjab State water department survey found that
1,166 of its nearly 7,000 projects were contaminated with heavy metals
including arsenic, uranium and arsenic beyond permissible limits”. Additionally the overuse of
nitrogenous fertilizer has in places seriously contaminated groundwater – the consequence
- contaminated food and drinking water, and an increased incidences of cancer
and other ailments. This problem also
occurs in the USA. The Salinas Valley in
California has serious nitrate
contaminated groundwater due to years of fertilizer use for intensive
agricultural cropping.
These are just a few examples of water pollution, there are
many more, at various scale on all continents.
There is an awful lot of discussion and planning in an attempt to
mitigate the problems; and in a few specific cases, normally associated with
industrial wastewater, there are positive actions with good results. However little is done on a wide scale
because of lack of political will, cost, lack of suitable technology, and the
inability of communities, landowners and businesses to address the problems
collectively.
The Vetiver System can provide the technology to address
some of the problems. Vetiver Phytoremediation Technology (VPT) has
the distinct advantage of relative low cost, low design complexity, and
application over a wide range of conditions.
VPT can be used for cleaning up and stabilizing mine dumps and landfills,
and treating the
leachate from such sites. It can be used
to remove agricultural
chemicals from the runoff from farmland and, preventing these chemicals
from entering groundwater and surface water drains and streams. One major strength of VPT is that not only
has it been proven extremely efficient in doing its job, but unlike most phytoremedial systems that are based on constructed
wetlands, VPT
works effectively under non wetland conditions thus allowing much wider
application. VPT takes up, at high
levels of concentration, most heavy metals, nitrates and phosphates and
agricultural chemicals including atrazine and endosulphan.
The Vetiver System has also been proven as a technology that
is liked by and is understandable to poorer communities. Thus we have examples
of community use for erosion control (in many countries including Indonesia), urban
ravine rehabilitation (Congo DR), wetland rehabilitation (Ethiopia), coffee
coop wastewater treatment (Ethiopia), slope stabilization (Madagascar), and
coastal infrastructure protection (Vietnam).
Wherever used, the applications have positive bi-products that include: carbon
sequestering, biofuels, mulch, and materials for handicrafts and industry -
real opportunity for a WIN WIN remedial program.
The contamination of soil and water can only get worse as
population increases and the demands on our land and water resources
increase. It needs action by civil
society as a whole and especially by communities associated with the most
contaminated areas to act. There are
many actions needed involving many agencies, and that action is needed
now. Vetiver Phytoremediation Technology is one such technology that
could be quite easily introduced on a wide scale, at minimum cost, to mitigate
some of these problems.
Dick Grimshaw – Last post for 2013!
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