Biotechnology Advances 18 2000 23–34
0734-975000 – see front matter © 2000 Elsevier Science Inc. All rights reserved. PII: S 0 7 3 4 - 9 7 5 0 9 9 0 0 0 3 4 - 8
Research review paper
Exploitation of plants for the removal of organics in environmental remediation
T. Macek
a,
, M. Macková
b
, J. Ká
b
a
Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo n. 2, 166 10 Prague, Czech Republic
b
Department of Biochemistry and Microbiology, Faculty of Food and Biochemical Technology, ICT Prague, Technicka 3, 166 28 Prague, Czech Republic
Abstract
This review concentrates on the description of various phytoremediation technologies, paying spe- cial attention to removal of organics and the application of in vitro systems for basic research in the
role of plants for the remediation of contaminated sites or flows, and in the improvement of their ef- fectiveness. Various aspects of xenobiotic metabolism in plant cells, the role of enzymes involved, and
the cooperation with rhizospheric microorganisms accelerating remediation of organics are shown. Application of this approach as well as the possibility of introduction of foreign genes into plant ge-
nome that can enhance the rate of the bioremediation are discussed.
© 2000 Elsevier Science Inc. All rights reserved.
Keywords: Phytoremediation; Xenobiotics; Polychlorinated biphenyls; Plant cells
1. Introduction
Phytoremediation is defined, according to Cunningham and Berti [1] and Cunningham et al. [2], as the use of green plants to remove, contain, or render harmless environmental con-
taminants. It is important to note that this includes the use of vegetation for in situ treatment of water, sediments, soils, and air. In this process specially selected or engineered plants can
be used for extraction of toxic metals from soil or water, including removal of radioactive el- ements, removal of toxic organic compounds, and, if possible, their mineralization.
sˇ
Corresponding author. Fax: 1
420-2-24310090. E-mail addresses:
tom.macekuochb.cas.cz T. Macek, martina.mackovavscht.cz M. Macková, jan.kas vscht.cz J. Ká
sˇ
24 T. Macek et al. Biotechnology Advances 18 2000 23–34
Cost comparisons of phytoremediation to other remediation technologies have recently been made. The consensus cost of phytoremediation has been estimated at 25–100 per ton
of soil treatment and 0.60–6.00 per 1000 gallons for treatment of aqueous waste streams. In both cases, the remediation of organic contaminants can be expected to fall at the lower
end of these ranges and remediation of heavy metals to fall at the higher end. In each ap- proach discussed, the expenses of phytoremediation represent less than half of the price
needed for any other effective treatment. According to 1997 U.S. EPA estimates, the cost of using phytoremediation in the form of an alternative cover vegetative cap ranges from
10000 to 30000 per acre, which is thought to be two- to five-fold less expensive than tradi- tional capping [3].
2. Advantages of phytoremediation
Phytoremediation has made tremendous gains in market acceptance in recent years. In ad- dition to its favorable economics, according to various authors [1,4–6] the main advantages
of phytoremediation in comparison with classical remediation methods can be summarized as follows:
It is far less disruptive to the environment. There is no need for disposal sites.
It has a high probability of public acceptance. It avoids excavation and heavy traffic.
It has potential versatility to treat a diverse range of hazardous materials.
Considering these factors and the much lower cost expected for phytoremediation, it ap- pears that it may be used in much larger scale clean-up operations than is possible by other
methods. The process is relatively inexpensive, because it uses the same equipment and sup- plies that are generally used in agriculture.
3. Disadvantages of phytoremediation
