Environmental Engineering Reference
In-Depth Information
electric field efficiency drives increased amount of soluble heavy metals toward
plant roots, which results in stress conditions for the plants, hyperaccumulator
plant with a rapid growth period are considered the best candidates for use in
combination with EK technique .Phytoremediation can be applied after EKR to
remove residual concentration of contaminants, and to achieve cleaner soil (Wan
et al.
2012
). The coupled EK-phytoremediation technology has showed very
promising results for the restoration of heavy metal contaminated soils, and may
lead to more effective and efficient remedial strategy as compared to the sequential
use of these technologies (Cameselle et al.
2013
).
17.6 Conclusion and Future Scope
Soil contamination is a global concern and disrupts the health of the biosphere in
numerous ways; as a result reduces the capacity of the soil to meet the needs of
future generation. There is an urgent need to develop an effective and affordable
technological solution. There are physical, chemical, and biological methods
available for such remediation, but effective remediation of polluted soils requires
accurate information on the distribution and behavior of contaminants as they
interact with soil and broader environment. The selection of each technique is site
specific. On site with a range of organic and inorganic pollutants present, com-
bination of different treatment approaches may offer the best prospect for effective
remediation. Physical treatment process is an inexpensive comparison to chemical
treatment, but most methods of physical treatments remove pollutants from the
complex polluted form for further treatment or disposal. Chemical process con-
verts the pollutant into less toxic form, or to extract them, or to immobilize them.
This is highly scientific and technical process, and requires expert manpower with
technological resources. Chemical additives increase the remediation cost and
in situ application also increases the chances of leaching of pollutant to the other
uncontaminated area and ground water. More field demonstrations are required to
match reactive media with contaminants, model lifetime performance, optimize
retention times, and develop methods for regeneration of reactive media. Bio-
logical methods include microorganisms (bacteria), soil invertebrates, and plant.
Various field of research are needed to optimize the efficiency of biological
methodology including identification of microorganisms capable of promoting
their degradation, and better systems for delivering microbes, and nutrients to
pollutants. Phytoremediation is environment friendly and cost-effective emerging
new technology for remediation of low to moderate area of contamination as well
as have important role in ecology restoration. The majority of the research for
phytoremediation has been conducted in laboratories under relatively controlled
conditions for short period of time.
Finally, to optimize the ecologic and economic efficiencies, it must be recog-
nized that we need to focus more on ecological engineering approach, which is
more sustainable. Assessing remediation progress and efficiency is also important,
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