various methods of Phytoremediation for abating water pollution and enhancing ecosystem services

2. Remediation - removing toxic or biohazard contaminants that
pose human health consequences or threats to the environment
from an infected area. Simply stated, remediation is a clean-up and
disinfecting process.

3. has been defined as the use of green plants and their
associated microorganisms, soil amendments and agronomic techniques to
remove, contain or render harmless environmental pollutants.

5. , the use of pollutant-accumulating plants to remove
metals or organics from soil by concentrating them in harvestable plant parts;

6. (phytodegradation), the
degradation of complex organic molecules to simple molecules or the
incorporation of these molecules into plant tissues;

7. , or plant-assisted bioremediation, the stimulation
of microbial and fungal degradation by release of exudates/enzymes into the
root zone (rhizosphere);

8. , is the uptake and transpiration of a
contaminant by a plant, with release of the contaminant or a modified form of
the contaminant to the atmosphere from the plant.

9. , the use of plant roots to ab/adsorb pollutants, mainly
metals, but also organic pollutants, from water and aqueous waste streams;

10. ,or in-place in activation and environment
restoration (IINERT) is the use of plants to reduce the mobility and
bioavailability of pollutants in the environment, thus preventing their migration
to groundwater or their entry into the food chain;

11. It can be performed with minimal environmental
disturbance;
It is applicable to a broad range of contaminants,
including many metals with limited alternative
options;
Possibly less secondary air and/or water wastes are
generated than with traditional methods;
Organic pollutants may be degraded to CO2 and H2O,
removing environmental toxicity;

12. It is cost-effective for large volumes of water having low
concentrations of contaminants; topsoil is left in a usable
condition and may be reclaimed for agricultural use;
Soil can be left at site after contaminants are removed,
rather than having to be disposed or isolated;
It is cost-effective for large areas having low to
moderately contaminated surface soils; plant uptake of
contaminated groundwater can prevent off-site
migration.

13. A long time is often required for remediation;
the treatment is generally limited to soils at a meter from the
surface and groundwater within a few meters of the surface.
Climatic or hydrologic conditions may restrict the rate of growth of
plants that can be utilized;
Contaminants may still enter the food chain through
animals/insects that eat plant material.
Potential of phytoremediation, an emerging green technology
Jean-paul schwitzguébel

18.  “A major effect of [wastewater] treatment with
plants was elimination of the disturbing smell …”
 Water Hyacinth – Heavy Metals
 Cattail, Reed – Nitrogen, TSS,
BOD, COD
 Degradation
Releases

20. Tangible
benefits
Bioenergy,
pulp and
paper,
lumber
Containers,
chopsticks,
Animal feed
Structural
composite
lumber
Composite
panels

21. Intangible
benefits
Carbon
sequestration
Soil erosion
control
Protection
plantings
Urban
plantings
environmental
regulation
Justice, and
aesthetics

22. Poplars and willows from phytoremediation systems are environmental acceptable
sources of biomass for bioenergy as well as wood products. Wood chips and/or pellets can
be mixed (co-fired) with coal to produce electricity.
This approach is cleaner, cheaper, and more environmentally acceptable than coal alone.

23. Planting a multi-species buffer of trees, shrubs, and grasses along streams in
agricultural areas have been shown to greatly decrease the soil erosion.
They moderate heat in summer and cold in winter for people and animals,
thereby enhancing land value, beauty, noise reduction, and wildlife habitat.

24. The potential use of trees as a suitable vegetation cover for heavy metal-
contaminated land has received increasing attention over the last 10 years
(Aronsson and Perttu, 1994; Glimerveen, 1996; EPA, 1999, 2000).
They redistribute surface contamination down the soil profile, causing a
reduction in the concentration near the soil surface (Robinson et al., 2003)
and distribute the heavy metals within the entire root zone for uptake.
They can be removed and ashed, the ash is then disposed of in a landfill or
other contained disposal area.

27. No company can legally be made responsible and be forced to pay for the
decontamination of land because the contamination by heavy metals historic activities.
Because the activities of biomass production and use can have a positive impact on the
economic development, especially in rural areas, authorities could have an interest in
phytoremediation.
The farmers are the group that would most benefit from phytoremediation.

30. The value is assessed via the economic benefits or costs of an alternative
approach; e.g., the value of water catchment service is assessed by calculating the
cost of additional reservoir capacity that would serve the same purpose (Randall,
2002).
In case of phytoremediation this method describes the cost of achieving a similar
environmental impact to that of biomass crop cultivation, but in another, relevant
and cost-efficient way.
The economic value of the phytoremediation function to farmers as assessed by
the substitution cost is about 14,600 € ha-1

31. Costs of phytoremediation by Thlaspi in the years 1–12
Costs for dumping the heavy metal contaminated biomass
Costs of vegetable production
Income from vegetable production
+
+
-

32. Measures the marginal value that is created by the function. Berndes et al. (2004) used
hedonic pricing for quantifying the economic benefit of cd removal by willow. The economic
value of the phytoremediation function is about 14,850 € ha-1
Income from selling willow biomass
The cost of willow production in years 1–6
Income from vegetable production
Cost of vegetable production in years 7–20
Income from cereal production
The costs for cereal production in the years 1-20
Additional cost for the combustion of biomass in the years 1-6

35. A direct method to assess the value of the service of the phytoremediation function
would be to find out at what price the service sells on the market.
There is, however, not yet a market for the phytoremediation service, but Glass(1999)
estimates 36-54 billion US$ phytoremediation market.
Phytotech Inc., a Monmouth junction estimates cost of phytoremediation of water to be
$2-6 /1000 gallons while conventional method costs $80/1000 gallons and $12 m/10
acre by conventional method and $ 500,000/10 acre by phytoremediation in lead
contaminated soil.

36. Many ecosystems services or on functions that are considered difficult to quantify (e.g.,
like landscape beauty) willingness-to-pay is attempted as valuation technique.
The potential advantage the willingness-to-pay method (WTP) offers, is that it reflects, in
a single monetary amount, the entire range of attributes (both benefits and
‘‘nonbenefits’’) offered by the good or service being valued (Blumenschein and
Johannesson, 1999).

37. This method, also referred to as contingent valuation method (Blumenschein and
Johannesson, 1999), is an indirect evaluation method.
Employs a questionnaire format where respondents are asked how much they would be
willing to pay (WTP) or willing to accept (WTA) for changes in the quantity or quality of a
given good or service in a market.
Major objections are that the results are biased and do rather reflect values on individual
than on society level, that individuals inquired may be ill-informed, might seek to answer
strategically or carelessly (Constanza et al., 1997; Randall, 2002; Zhang and Li, 2005).

40. Sensitivity analysis
With the substitution cost and economic benefit method a sensitivity analysis was
done for those parameters that have the strongest influence on the value of the
phytoremediation function.
 The length of period that the farmer is planning to use the land after it has
been cleaned.
 The height of potential income from the contaminated area after it has been
cleaned
 The extent of contamination, i.e., The concentration of heavy metals in the soil
and the time needed to clean the soil.

42.  Identifying more species that remediative abilities.
 Optimizing phytoremediation process, such as appropriate plant selection and
agronomic practices.
 Understanding more about how plants uptake, translocate. And metabolize
contaminants.
 Identifying genes responsible for uptake and/or degradation for transfer to
appropriate high-biomass plants.
 Decreasing the length needed for phytoremediation to work.
 Devising appropriate methods for contamination of biomass.

43. Phytoremediation processes hold great promise as means to
clean-up polluted soils and water.
In addition to remediation technology it provides appreciated
ecosystem services (biomass, soil erosion control, wild life habitat
etc.)
Steps are to be taken in exploiting the potential of plants for
remediation of various xenobiotics in the environment.
In addition to technical barriers, government regulations will also
determine the overall success of phytoremediation.