Phytoremediation of Chemical Explosives
Creation of a Novel Complex Phytoremediation Technology for Rehabilitation of Soils and Waters Polluted with Explosives
Tech Area / Field
- ENV-RED/Remediation and Decontamination/Environment
- ENV-SPC/Solid Waste Pollution and Control/Environment
- ENV-WPC/Water Pollution and Control/Environment
8 Project completed
Senior Project Manager
Smirnova N V
Durmishidze Institute of Biochemistry and Biotechnology, Georgia, Tbilisi
- Institute of Biochemistry and Physiology of Microorganisms, Russia, Moscow reg., Puschino
- Cranfield University / School of Industrial and Manufacturing Science, UK, Beds, Cranfield
Project summaryMain goal of the Project is development of a novel phytoremedation technology, the essence of which is a three-stage process of biological treatment of soils and water reservoirs polluted with explosives TNT and RDX. The novel technology based on combined action of plants and microorganisms will direct their common detoxification potential to rehabilitation of the environment polluted as a result of military activities.
TNT (2,4,6-trinitrotoluene) and hexogen (hexahydro-1,3,5-trinitro-1,3,5-triazine) or cyclonite or, according to the British code name, RDX) are the most toxic compounds among explosives in the military arsenal. Production and application of these compounds results in their dispersal in the environment, which leads to much harm to all living organisms. Undoubtedly, the most effective and economically profitable technology for rehabilitation of chemically polluted environment is phytoremediation based on the unique properties of plants and microorganisms to assimilate and degrade the wide range of toxic compounds. This approach allows without affecting soil structure complete remediation of chemically polluted sites with maintenance of ecological balance. The following major goal is pursued:
Maximal decrease in concentrations of toxic compounds in soil and water by way of their uptake and degradation by plants and microorganisms to standard cell metabolites and carbon dioxide.
The problem with phytoremediation (transformation) of TNT and RDX is their low solubility resulting in inefficient absorption by plant root system. After penetration into plant cells they remain highly stable and their degradation proceeds very slowly. These compounds undergo only partial transformation in plant cells and accumulate mainly in the form of conjugates with cell polymers. As a result, in plants the explosives maintain the most part of molecule chemical structure, which determines their toxicity. Certainly, plant biomass used in phytoremediation must undergo special processing, e.g., burning at a high temperature for complete detoxification.
The project offers a new strategy to solve the problem of phytoremediation of explosives, the essence of which is to achieve the maximal degree of neutralization of toxic compounds through creation of the following three-stage system of phytoremediation:
- At the first stage (“rhyzosphere biodegradation”), rhyzosphere microorganisms selected specifically for this purpose are introduced into a polluted object (soil, water); microorganisms realize initial transformation of explosives, converting them into comparatively less toxic, more hydrophilic compounds which are much easier assimilated by plants.
- At the second stage (“phytoextraction and phytotransformation”), plants with a high phytoremediation potential remove explosives and/or intermediates of their partial transformation from polluted object. At this stage, biostimulators (INAGROSA, Industrias Agrobiologicas, S.A.) will be used to activate metabolic processes and thus to intensify phytoremediation activity of plants.
- At the third stage (“bioutilization”), plant residues used in phytoremediation will be treated with microorganisms (basidial fungi) having powerful oxidative enzyme systems that degrade toxic compounds.
Realization of a project would allow creating cost-effective environmentally friendly, technology without genetic modification.
Participants of the project are scientists from IBB and IBPM.
At IBB, they have been studying detoxification abilities of plants and microorganisms since 1960 (the list of select recent publications is given in 12.2). In the past period, more than 100 chemical toxicants have been studied and about 150 representatives of annual and perennial plants have been tested on their detoxification abilities. IBB has culture collections of microorganisms of different taxonomic groups (actinomycetes, bacteria, yeast, microscopic and basidial fungi) with previously investigated bioremediation abiilties. IBB researchers have accomplished the following ISTC projects analogous in subject to the project proposed:
G-369 – “Development of methods of bioremediation of contaminated soils on former military locations and proving grounds in Georgia” (2001-2004).
G-718 – “Development of a novel strategy for phytoremediation and long-term protection of environment polluted by hydrocarbons” (2002-2005).
IBPM researchers have a many-year experience in the study of microbial biodegradation of a wide range of organic pollutants and bioremediation of soils polluted with toxic compounds such as chlorine-, sulfur- and phosphorus-containing pesticides, chlorophenols, volatile aromatic hydrocarbons, oil, creosote, PAH (the list of select recent publications is given in 12.3). The laboratory has a unique collection of microorganisms – destructors of pollutants including those with high stability in the environment, and developed approaches to purification of soil and water polluted with different toxicants.
IBPM has as its part the All-Russian Collection of Microorganisms with over 15,000 microbial cultures stored and maintained, which make up to 70% of the total species stock of Russian collections. IBPM researchers participated in the national and international projects on microbial degradation of xenobiotics, including International NATO Award “Science for Piece” SfP972294 (1999-2003) “Degradation of chlorophenols by ligninolytic fungi”, international projects Inco-Copernicus 1 and 2 #IC15-CT96-0103, ICA2-2000-10006, “Bioremediation of water”, international project INTAS #03-51-5889 “Blue and non-blue laccases of basidiomycetes”, RFBR-Germany grants #436RUS 113/59/0, SCHL 284/2-2.
The foreign collaborator, Professor E. Best, is one of the leading experts in the field of phytoremediation of explosives. Her role in the project is active participation in research work planning, discussion of results and findings, preparation of publications, consultations, participation in conferences and review of reports.
Results of the project will become a basis of a scientifically based strategy for regulation of ecophysiological characteristics of plants and microorganisms for maximal expression of their phytoremediation potential and, eventually, creation of a novel ecological biotechnology of general run for rehabilitation of soils and water on the territories of military actions, proving grounds, dislocations, military plants and storehouses.
The International Science and Technology Center (ISTC) is an intergovernmental organization connecting scientists from Kazakhstan, Armenia, Tajikistan, Kyrgyzstan, and Georgia with their peers and research organizations in the EU, Japan, Republic of Korea, Norway and the United States.
ISTC facilitates international science projects and assists the global scientific and business community to source and engage with CIS and Georgian institutes that develop or possess an excellence of scientific know-how.