Natural Remediation of the Soil
Searching of Natural Mechanisms for Remediation of the Soil from Technogenic Polluters
Tech Area / Field
- ENV-RED/Remediation and Decontamination/Environment
3 Approved without Funding
Kyrgyz Research Institute of Livestock, Veterinary and Pastures, Kyrgyzstan, Bishkek
- University of Northern British Columbia, Canada, BC, Prince George
Exposure of promising plants and rhizosphere microorganisms able to live in natural conditions and rehabilitate the top-soil by its refinement and purification from man-caused negative influence and pollution.
The Kyrgyz Republic is one of the region where the process of top-soil destruction is very intensive. About 88 per cent agricultural land out of 10.047, 000 mln. hectares in overall have been acknowledged to be destructed. The problem of the lack of ploughed land has doubled in amounts. Plough land per capita has also decreased. Soil destruction can be referred to many factors, such as changing climate, imperfection of used in agriculture equipment and technology, mining operations, development of oil and gas fields, man-caused catastrophes and test of armament.
On of the most important negative factors in soil destruction has man-caused pollution of soil by heavy metal, uranium from dumps and tailing pits. There are about 47 uranium tailing pits, and 80 dumps in the Kyrgyz Republic. They contain dangerous for population health elements. Capacity of gamma rays on the to-soil is about 20-50 and more mcR/h. Content of Se, Cr, Pb, Zn exceeds maximum permissible rate 98 times.
Another source for soil destruction is heavy metal and aromatic hydrocarbon due to the development and production of oil and gas and increasing number of auto transport. Researches made in 2000-2004 not far from industrial centers (Bishkek, Kara-Balta, Tokmok and Orkovka) and oil production centers (Uzgen) have revealed that about 71 per cent of exudates elements are of the first and second class of dangerous elements. Poluttion is mainly due to Cr and Pb. Analysis of the soil sample showed overall existence of fuel remnants (fuel perineum).
Urgency of the problem is in high density of regions suffering from the soil destruction, which are in a zone of high seismic risk in addition.
Moreover, this problem is aggravated by current operation of gold mining and mining companies, such as Cumtor, Makmal, Khaydarkan Mercury Plant and Kara-Balta Mining Plant. In the near future it is also envisaged to start development of new deposits in Talas and Chuy oblasts. It is also planned to increase oil and gas production.
Such a situation results in irreversible process and lost of agricultural land. For the period of 1998-2004 there was lost about 46.5 k. hectare of land which have been recognized as useless and/or of little use. This includes the land polluted by heavy metal, uranium and aromatic hydrocarbons.
Therefore, the problem on rehabilitation and purification of soil from man-caused pollution is not only of environmental but is of social importance also. Thus, recultivation and remediation of destructed soil is of high urgency nowadays. Many efforts are made in the Republic in search of and development of effective and modern technologies to solve this problem. It have been therefore attracted as domestic resources so foreign investments.
Existing methods for remediation and recultivation conditionally can be pided into two categories, these are physical-chemical and bio-technological. The main method for recultivation today is a physical-chemical one. Unfortunately, these methods can not radically solve the problem of soil destruction, since it is required to restore biocenose, stimulate for humus formation and fertility restoration.
One of the major directions is in search for natural mechanisms for soil purification and delay of soil destruction process. We propose to use ability of plants and rhizosphere microorganisms to accumulate and destructure different types of pollution. In such an effort there have been undertaken several researches by the members of our project. Surveys have shown content of some metal e.g. Cu and Co in composite and bean plants, which can accumulate heavy metal and reduce content of fuel-oil residue in the soil. For example, Medicago sativa (lucerne) together with rhizosphere microorganisms can reduce content of bitumen in soil by 75 per cent. We have also some planted some sorts of bean plants i.e., Medicago sativa (Lucerne) «Bereke», sainfoin Onobrychus «Belek» and grain cultures i.e., cocksfoot Dactilys glomerata «Maria» that can be used for recultivation.
We have also surveyed chemo and radio sensitivity of plants depending on their geographic origin. It have been revealed that some plants can accumulate metals regardless of their environmental zones, this includes sharpleaf willow Salix songorica (accumulates Zn), grey Eurotia ceratoides (Sr), ephedra horse-tail Ephedra equisetina (Ca), tobacco Nicotina tabacum can decompose trinitrotoluene (TNT).
On the basis of data obtained we can state that selected direction in researches is one of the most prospective ways for rehabilitation and renovation f the territories from man-caused pollution.
Effective implementation of the project requires following activities:
- Define content of heavy metal, uranium, aromatic hydrocarbons in the soil and plants in the regions of Kara-Balta Mining Plant, Orlovskiy Mining Enrichment Plant, and Bishkek, Kara-Balta, Orlovka and Uzgen towns.
- Reveal prospective plants which can be used for rehabilitation of polluted territories and develop herbarium and field collection.
- Survey rhyzosphere microflora of plants taken from the man-caused polluted zones.
- Develop the map of the region describing the state and level of soil destruction.
- Develop a special technology to use plants and microorganisms for rehabilitation of soil and delay of destruction process.
Meeting ISTC Goals and Objectives.
The proposed project meets ISTC goals and objectives: “To support fundamental and applied research and technological development for peaceful purposes especially in the area of environmental protection…” The project provides to scientists and specialists in Kyrgyzstan who were previously involved in weaponry production opportunities to reorient their activities and skills for creation new technologies to rehabilitee polluted territories and transfer them into healthy zones. The project realization will further a creation of new work places for weapons scientists and integration of scientists from Kyrgyzstan into the international community. This, in its turn, will impact positively on further scientific researches in the areas of ecological independence and food safety.
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.