Agriculture Reference
In-Depth Information
Variety of contaminant-degrading enzymes can be found in plants. These include
peroxidases, dioxygenases, P450 monooxygenases, laccases, phosphatases, dehalogenases,
nitrilases, and nitroreductases (Susarla et al., 2002; Singer et al., 2004 Chaudhry et al., 2005).
Phytoremediation is based upon the basic physiological mechanisms taking place in higher
plants and associated microorganisms, such as transpiration, photosynthesis, metabolism,
and mineral nutrition. Plants dig their roots in soils, sediments and water, and roots can take
up organic compounds and inorganic substances; roots can stabilize and bind substances on
their external surfaces, and when they interact with microorganisms in the rhizosphere
(Marmiroli et al., 2006). Uptaken substances may be transported, stored, converted, and
accumulated in the different cells and tissues of the plant. Finally, aerial parts of the plant
may exchange gases with the atmosphere allowing uptake or release of molecules
(Marmiroli et al., 2006). A series of six phytotechnologies have been identified by Interstate
Technology and Regulatory Cooperation (ITRC, 2001) which may address different
contaminants in different substrates, and which rely on one or more of the plant properties.
1.
Phytotransformation, ideal for organic contaminants in all substrates
2.
Rhizosphere bioremediation, applied to organic contaminants in soil
3.
Phytostabilisation, for organic and inorganic contaminants in soil
4.
Phytoextraction, useful for inorganic contaminants in all substrates
5.
Phytovolatilisation, which concerns volatile substances
6.
Evapotranspiration, to control hydraulic flow in the contaminated environment
4. Conclusion
Remediation of hydrocarbon contaminated soil is a necessity in order to have a safe and
healthy environment that will in turn results in healthy lifestyle across the globe. Biological
remediation of hydrocarbon and metal contaminated soil offers a better and more
environmentally friendly technique that if properly and thoroughly explored can bring our
environment into a better place for both plant and animals well being due to its enormous
advantages over other treatment methods. However, despite these enormous advantages of
biological treatment method, its potential is yet to be fully utilized in restoration of
contaminated soil. This is possibly due to the fact that it takes a longer period of time for the
complete restoration of the environment; this limitation can however be overcome through
nutrient addition and introduction of microbes with biodegradative capability to degrade
hydrocarbon and heavy metals in the environment. Future research and developments will
requires focus on the use of cheap, environmental friendly and widely available nutrients
that can be used to enhance the microbial and plant activities in mineralizing hydrocarbons
and heavy metals in soil environment.
5. References
Abhilash, P.C., Jamil, S., Singh, N. (2009) Transgenic plants for enhanced biodegradation
and phytoremediation of organic xenobiotics, Biotechnology Advance 27: 474 - 488.
Abioye, O. P, Abdul Aziz, A, Agamuthu, P. (2009b). Stimulated biodegradation of used
lubricating oil in soil using organic wastes. Malaysian Journal of Science. 28(2): 127
- 133.
Abioye, O. P, Abdul Aziz, A, Agamuthu, P. (2010). Enhanced Biodegradation of Used
Engine Oil in Soil Amended with Organic Wastes. Water Air and Soil Pollution.
209: 173 - 179.
