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8STUDY OF FILL-UP SOILS OF THE INDUSTRIAL REGION OF GEORGIA
(BOLNISI - KAZRETI)
Rusudan Gigauri
Doctor of Science (Engineering), Senior Researcher, TSU-based R. Agladze Institute of Inorganic Chemistry and Electrochemistry Guranda Avkopashvili
Academic Doctor of Chemistry,science worker, TSU-based ElevterAndronikashvili Institute of Physics
Lasha Khvichia
Chemical Analyst, Institute of Hydrology and Engineering Geology of GTU Manuchar Chikovani
Doctor of Science (Chemistry), Associate Professor, Kutaisi Ak.Tsereteli State University
Abstract.In the industrial regions of Georgia (Bolnisi-Kazreti) fill-up soils were studied in order to determine soil fertility levels. It was found that the fill-up soil belongs to the heavy and medium sandyclay soils, with a low nutrient level and average cation exchange capacity (CEC). From toxic elements MAC is violated in the case of zinc and copper.Mobile soluble forms of heavy metals in soil have been studied using EPA test methods. The results show that heavy metals are mainly accumulated in the soil.Mobilesoluble forms of heavy metals range only from 5% to 10%. The fill-up soil is subject to restoration-recultivation.The study uses modern methods of physico-chemical analysisensuring a high degree of accuracy in the determination of inorganic and organic compounds.
Keywords:humus, soil, capacity, forms, recultivation, metals
Scientific and technical progress has led to the pollution of wildlife, which is already an irreversible process. About 23% of deaths worldwide are caused by water, air and soil pollution. Particular attention is paid to pre-monitoring of the soil in order to identify harmful substances in it.Kvemo Kartli, one of the most beautiful regions of Georgia, is an industrial area where gold and copper are mined by JSC "RMG COPPER" and "RMG GOLD". Visual images of mines are presented below:
Fig.1. Gold quartzite mine Fig.2. Copper chalcopyrite mine
The modern world is facing the biggest problem. The population is growing and respectively their demand for agricultural products is going up. Hence, the anthropogenic impact on biodiversity is enhanced. Along with agriculture, man introduced the concept of soil as a relatively loose soil layer in which the plant takes root and therefore, becomes the arable land. For many millennia, people have not been concerned with agricultural problems such as catastrophic erosion, desertification, land shortage, declining fertility, and etc. Today, the world is facing all these problems that need to be solved. [5].
The region we are considering is characterized by subtropical climate, gray-meadow soilswith weak alkaline reaction, and low or medium humus content,thatare carbonated, and high in calcium and iron content.We aimed at studying fill-up soils of this industrial region in order to provide the green cover for these areas, even in the form of plants, taking into account the remediation-recultivation conditions. A visual image of fill-up soils is provided below:
Fig.3. Surface of the fill-up soil
Fig.4. Depth of the surface
Up to 20 units of fill-up soil samples were taken for the study and were processed for further analysis. Soil acidity and nutrients have been determined. The results are presented in the table below. [1] [2].
Table №1
Nutrient Content of Soil
# Nutrients in Soil (fill-up)
pH N mg/100 P mg/100 K mg/100 Mg % Ca % Fe % Na % S % SO42- - %
1 6 1.64 0.16 13.5 1.2 4.4 4 5 0.014 0.045
2 5.5 1.25 0.037 10.0 1.5 4.5 4.8 4 0.015 0.048
3 7 1.8 0.082 11.8 2 5 4.5 5 0.014 0.045
4 6 1.1 0.052 9.8 1.8 4 5 5 0.0138 0.041
5 6 1.39 0.1129 11.3 1 4 5 5 0.014 0.045
6 5.5 0.83 0.08 8.3 2 5 4 4 0.0165 0.05
7 7 1.6 0.15 10.0 2.5 5 4 5 0.0165 0.05
8 6 0.9 0.082 8.2 1.5 4 5 4.5 0.0132 0.04
9 6 1.39 0.16 10.3 1 4 4.2 5 0.014 0.04
10 6 1.8 0.033 8.6 1.5 4 5 5 0.0132 0.05
11 6 2.9 0.113 10.6 2 4.5 5 5 0.0165 0.045
12 5.5 1.6 0.052 8.1 1.5 4 5 4 0.014 0.04
13 5 1.9 0.075 8.0 1 4 5 3.8 0.013 0.04
14 5.5 2.0 0.15 9.5 1 3 5 3 0.013 0.045
15 6 1.0 0.052 8 1.5 4 4.8 3.5 0.014 0.05
16 6 1.6 0.158 9.7 1.2 4 5 4 0.016 0.04
17 5.5 0.9 0.075 7.7 1 3 5 3 0.013 0.048
18 6 1.8 0.13 9.8 2 4 4.8 4 0.015 0.04
19 6 0.9 0.033 7.8 1.5 4 5 4.5 0.013 0.04
20 5.5 1.3 0.15 9.4 1 3 5 3 0.006 0.02
Based on the results, it was determined that NPK is low in content. Since nitrogen is less than 4mg/100g. its content is defined as low.Considering P2O5,that is less than -2.5 mg/100 g., it is defined aslow. ConsideringK2O, that is less than 8 mg - 15 mg/100 g., it is defined as low.The content of the other nutrients is much better and is between low and medium. Fill-up soils to be studied are characterized by superficial hardening which indicates that the top humus layer is poor or almost barren. The percentages of theorganic material such as sand, silt, clay, loamhave been determined.
Table №2
Percentages of the Organic Material in Soil
№ sand silt clay loam
% % % %
1 50 19 25 5
2 38 5.1 48 8.0
3 28.3 26.6 30 15
4 26.0 12.6 58 3
5 26.6 33 23.3 15
6 53.3 19 18 9
7 30.0 22.5 40 7.0
8 26.0 15 56 2.8
9 26.0 26 39.3 8
10 27.3 22 43.3 6.6
11 22.0 29 40 8
12 29.0 15 49 6.3
13 78.0 8 11 2.3
14 35 23.0 36.3 5.3
15 29.0 9.0 60 1.6
16 16.0 3.6 40 10
17 20.0 10 66.6 3.3
18 60.0 20 15 5
19 56.6 18.6 16.3 6.6
20 61.0 18 15.3 5.6
Percentages of the organic materialindicate that the fill-up soil is of heavy and medium sandy-clay type. Based on the results, there is a hope that the soil structure can be improved as a result of soil reclamation and remediation.We also considered it necessary to study the cation exchange capacity (CEC) in the soil, which is the ability of exchanging cations. They bindto negatively charged particles resulting in the soil becoming a reservoir of plant nutrients. The volume fraction of organic matter is determined by the buffering capacity and clay content.
Table №3
Results of Cation Exchange Capacity (CEC) in Soil
№ Ca mg/Eq/100g. Mg mg/Eq/100g. Na mg/Eq/100g. Sum Base Saturation %
Ca% Ca% Ca%
1 13.0 5.0 4.7 22.7 57.3 22.1 20.3
2 12.0 5.0 4.5 21.5 55.8 23.3 20.9
3 12.5 4.8 5.0 22.3 56.05 21.5 22.4
4 13.0 4.0 5.0 21.8 59.6 18.3 22.9
5 12.8 5.0 4.5 21.5 59.5 23.3 20.9
6 12.0 4.5 5.0 21.5 55.8 20.9 23.3
7 11.5 4.0 4.0 19.5 58.97 20.5 20.5
8 11.0 3.8 4.0 18.8 58.5 20.0 21.2
9 11.0 3.5 4.0 18.5 59.5 28.9 21.6
10 10.8 3.5 4.0 18.5 58.4 18.9 21.6
11 10.5 3.5 4.5 18.5 56.7 18.9 24.3
12 10.0 3.0 4.0 17.0 58.8 17.6 23.5
13 10.0 3.0 4.0 17.0 58.8 17.6 23.5
14 10.5 3.0 4.0 17.5 60.0 17.1 23.5
15 10.0 3.0 4.0 17.5 58.8 17.6 23.5
16 9.5 3.0 4.0 16.5 57.5 18.0 24.2
17 9.0 3.0 4.0 16.0 56.2 18.8 25.0
18 9.5 3.5 4.0 17.0 55.8 20.6 23.5
19 9.0 3 4.0 16 56.2 18.8 18.7
20 9.5 3 4.0 17 55.8 17.6 23.5
Based on the results, there is a small reservoir of nutrients and the sum of the saturated bases in the soil in the form of cations. The main taxonomic unit of soil structure classification is a soil type. The soil structure is formed by the ratio of air to water. Damaged soil structure means that humus is degraded, the content of nutrients is decreased, a hardened layer is formed in the upper humus, water permeability, moisture and aeration are impaired. We are dealing with soil exhaustion, i.e. (C:N=25-30:1). Research has been carried out in this direction as well, and the classification of the structure of the study soil has also been conducted.
Table №4
Results of Soil Structure Classification
№ General Organics % Humus % Density Soil type Porosity Moisture-Capacity
1 1.6 0.75 m S « M i/o VO Sandy - clay soil 30 - 35% 40 - 45%
2 1.4 0.65
3 2.6 1.20
4 1.5 0.70
5 2 0.94
6 2 0.94
7 3 1.40
8 2.2 1.03
9 3 1.40
10 1.6 0.75
11 2.4 1.13
12 1.4 0.65
13 2.8 1.30
14 2 0.90
15 1.4 0.65
16 1 0.47
17 1.8 0.84
18 1.8 0.84
19 1.2 0.56
20 1 0.47
An indicator of soil structure shows that the soil is barren and exhausted, i.e. it cannot be considered to be fertile. In addition, the soil structure allows it to be restored, or subject to restoration. We consider it necessary to use combined organic fertilizers for recultivation to restorefill-up soils. Toxic elements have also been identified in the fill-up soil that is shown in the table below:
Table №5
Concentration of Toxic Elements in Soil
# Toxic elements mg/kg
As Pb Cd Cu Zn Mn Ni Ti Sb Hg
1 0.37 1.0 0.1 50 10 1.0 2.0 1.2 0.02 No
2 0.7 1.2 0.1 50 10 1.0 2.0 1.0 0.02 No
3 0.7 0.9 0.1 35 10 1.0 2.0 1.0 0.02 No
4 0.7 1.0 0.1 40 9 0.99 2.0 1.0 Traces No
5 Traces 1.0 0.1 40 9 0.99 2.0 1.0 Traces No
6 0.74 1.5 0.1 50 9 1.0 2.0 1.2 1.02 No
7 Traces 1.0 0.5 50 8 1.0 2.0 1.2 No No
8 No 1.2 0.1 40 9 0.9 2.0 1.2 No No
9 Traces 1.0 0.1 40 9 0.9 2.0 1.2 No _
10 0.7 1.4 0.1 50 10 1.0 2.0 1.0 1.02 _
11 Traces 0.8 0.1 35 9 0.5 2.0 1.0 No _
12 No 1.0 0.1 35 8 0.5 2.0 1.2 No _
13 No 1.0 0.1 40 9 0.5 2.0 1.2 No _
14 Traces 1.2 0.1 50 10 1.0 2.0 1.0 No _
15 0.03 1.0 0.1 50 10 1.0 2.0 1.0 Traces _
16 No 0.8 No 35 8 0.5 2.0 1.2 No _
17 No 0.8 No 35 8 0.5 2.0 1.0 No _
18 0.03 1.0 0.1 30 8 1.0 2.0 1.0 Traces _
19 Traces 1.0 0.1 30 9 1.0 2.0 1.0 No _
20 No 1.0 0.1 30 9 1.0 2.0 1.0 No —
Based on the results, among the toxic elements copper and zinc are twice as high as MAC. Ecologically safe soil means environmentally friendly environment and production. The study of toxic elements has been carried out using EPA test methods which involves the extraction of toxic elements for their further determination [4] [5]. CONCLUSION
As a result of the study of fill-up soils of Bolnisi-Kazreti industrial region of Georgia, it was determined that the soil is heavy and of a medium sandy-claytype with low nutrient content, havingthe average value of cation exchange capacity (CEC). Using EPA test methods (TCLP and WET) the content of toxic heavy metals in the soil and their mobile soluble forms were determined, that range from 5% to 10%.It indicates that heavy metals are mainly accumulated in the soil.The research carried out on the fill-up soil creates the possibility of its further restoration-recultivation through organic and combined fertilizers. Restoring fill-up soils with green cover is our primary goal as well as changingthe barren, infertile environment into a fertile one and cover it with greenery. Modern methods of analysis have been used in the study: quantitative-spectral ISP-30, quantitative chemicaliodometry, complexometry, gravimetry, atomic absorption spectrometry, X-ray fluorescence spectroscopy, EPA test methods.
References:
[1]. E. V. Arinushkina Manual on Chemical Analysis of Soil2011. PDF.
[2]. G.S. Fomin, A.G. Fomin Soil, Quality Control and Ecological Safety According the International Standards 2001-2015. ISBN 5-900631-06-0 (ISO)
