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THE TECHNOLOGY OF CREATION

THE TECHNOLOGY OF CREATION OF PROTECTIVE HYDROCARBON-IMPERVIOUS SCREENS IN SOILS PREVENTING DOWNWARD MIGRATION OF HYDROPHOBIC CONTAMINANTS. Irina Breus, Sergey Neckludov, Vladimir Breus , Konstantin Potashev Kazan State University / Institute of Chemistry Kazan, Tatarstan, Russia

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THE TECHNOLOGY OF CREATION

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  1. THE TECHNOLOGY OF CREATION OF PROTECTIVE HYDROCARBON-IMPERVIOUS SCREENS IN SOILS PREVENTING DOWNWARD MIGRATION OF HYDROPHOBIC CONTAMINANTS Irina Breus, Sergey Neckludov, Vladimir Breus, Konstantin Potashev Kazan State University / Institute of Chemistry Kazan, Tatarstan, Russia Email: ibreus@ksu.ru ISTC #2419 Financing: USA, $ 250 000 Duration:30 months, completed ISTC #0372 (funds for PCT patent application) 1

  2. The problem of oil contamination Oil transportation system in Central Russia Contamination removal at oil spill Hydrocarbon pollution of soils and groundwater as a result of emergent spills of oil and petroleum products Fact sheet US Geological Survey FS-019-98(January 1998) 2

  3. The approach and objective of the work A preventive approach to the solution of the investigated problem was offered. First of all, it provides for the protection of lower soil layers and therefore of groundwater from organic hydrophobic contamination Oil recovery and oil refinery are the main sources of environmental contamination with hydrocarbons The objective of work to develop a scientifically-based, efficient, low-cost and environmental-friendly technology of subsoil and groundwater protection against hydrocarbon (HC) contamination, based on the study of processes of HC binding and migration in soils with inserted natural sorbents 3

  4. The most widespread scenarios of entering HC contaminants into the soil Two the most widespread scenarios of entering HC contaminants into the soil - • as liquid NAPL phase (as a result of oil emergent spills and leakages), and • as HC vapours - were provided for in the technology The problem of soil protection against the spills of hydrophobic organics could not be completely solved only on the basis of sorbents. Some additional mechanisms of immobilization of organic contaminants should be involved. Raymond L. Frigon, Jr., D.E.P. Bureau of Water Management 4

  5. Hydrophobic anti-filtration screens (barriers) for soil and groundwater protection Impervious barrier (polymers, cross-linked polymer foam, suspensions, hydraulic barriers) Isolation barrier (clay, bentonite geotextile, geomembranes, polymer films, concrete base) • The methods of restriction of flow of liquid contaminants in soils by creation of solid or liquid hydrophobic anti-filtration screens, impermeable or semi-impermeable are reported • However, such approaches cause alteration of water-physical properties and thus, of water regime of soils and subsoils • The technologies are also reported in which contaminant’ migration is prevented due to creation of a hydraulic barrier formed by water injection into the polluted area • However such a method is more complicated technically, more expensive and also causes sharp increase of watering soils and subsoils 5

  6. Main tasks The final task - the creation of a sorption-hydraulic barrier that could be • efficient, • cost-effective, • ecologically safe • not disturbing water-physical properties of a zone being protected from HC contamination The main tasks • to estimate natural soil barrier functions towards HC of various chemical nature • to assess the role and relative contributions of the key processes (sorption, capillary retention, diffusion, swelling) to the retention of aliphatic and aromatic HC • to compare the results of HC flow experiments and HC sorption and capillary retention data • to estimate the impact of natural sorbents on HC sorption, to select sorbents improving soil barrier features, to identify optimal conditions for their use in flow experiments (type of sorbent, doses and methods of placing them into soil, soil moisture) • On this basis, to develop a technology for soils and groundwater protection against HC contamination 6

  7. Soils and contaminants Location of soil sampling (Tatarstan, Russia) Hydrocarbons Aliphatic • n-Nonane • n-Tridecane Alicyclic • Decaline Aromatic • Benzene • 1-Methylnaphtalene (1-MN) Hydrocarbon mixtures 7

  8. Sorbents • Mineral sorbents • Zeolite-containing material (ZCM), Tatarstan, Russia • Zeolite St. Cloud (Z), USA • Bentonite clays, Russia • Organic sorbents • Peat • Cellulose • Tree bark • Rubber crumb ZCM Z 8

  9. Filtration experiments 15 ml Primary pollution Secondary pollution 2 3 2 cm 5 HC mixture Water Analyses Sampling and extraction 4 Glass column CCl4 1 Native soil sample Receiver 9

  10. Estimation of soil native barrier functions Transport of HC mixture (nonane-tridecane-decaline-1-methylnaphtalene, 1:1:1:1) in leached chernozem moistened up to field capacity: HC and water distribution in the soil profile after 10 month of filtration The 40 cm-layer of leached chernozem under field capacity essentially stoped downward HC migration to the lower soil layers up to groundwater 10

  11. Swelling of soil particles in soil water environment Swelling of soil particles in soil water as one of the reasons of stopping HC front in middle- and heavy-loam soils Water 11

  12. ELECTROPNEUMATIC VALVE SPLITTER FUSED SILICA COLUMN VIAL WITH SAMPLE THERMOSTATE Sorption experiments Measurement of sorption isotherms of hydrocarbons: Static gas chromatographic headspace analysis method Approximation of isotherms: MGAB equation I.Breus, A.Mishchenko, K.Potashev, V.Breus // Coll. and Surf. A., 276 (2006), N1-3, 122–133 Gorbatschuk V.V., Smirnov S.A., Vishnyakov I.M., et al. Patent 1567973 SSSR, B. I., 1990, N20. Screenshot of the program for work in the sorption database 12

  13. HC vapors sorption under various moisture conditions(Soil & Mineral sorbents) Oven dried 105 oC RH=100% Sorption isotherms of benzene on leached chernozem and natural mineral sorbents under various moisture conditions:  Leached chernozem  Zeolite-containing material  St. Cloud zeolite  Biklyansky clay 13

  14. HC vapors sorption under various moisture conditions(Mineral & Organic sorbents) Oven dried 105 oC RH=100% Sorption isotherms of benzene onnatural mineral and organic sorbents under various moisture conditions:  Zeolite-containing material  Peat  Tree bark 14

  15. The effects of additives on HC filtration in soils(local ZCM) Effect of addition of 1 wt. % ZCM into the upper soil layer: Distribution of HC (mixture of nonane-tridecane-decaline-1-methylnaphtalene, 1:1:1:1) and water in the profile of leached chernozem moistened up to field capacity Effect of ZCM addition into the upper soil layer: Water distribution in the profile of leached chernozem moistened up to field capacity. ZCM inserted in the dose not less than 1 wt.% into the top layer of moistened leached chernozem practically completely blocked HC downward migration due to enhancement of a hydraulic barrier (water retention increasing) in the soil 15

  16. The effects of additives on HC filtration in soils(Organic sorbents) Tree bark (5 wt.%) Peat (5 wt.%) Effect of addition of natural organic sorbents into the upper soil layer: Distribution of HC (mixture of dodecane and 1-methylnaphtalene, 1:1) and water in the profile of leached chernozem moistened up to field capacity Organic materialsinserted into the soil also caused stopping HC front. The effect was associated to a great extent with HC absorption by these additives 16

  17. Water Water Technology Elaboration:Sorption-hydraulic barriers for preventing downward hydrophobic HC migration in soils The efficiency of developed barriers is reached by inserting into the top soil layer of natural mineral and organic materials, chosen based on their high water-retention properties due to capillary and sorption forces, with further moistening of soil layer containing sorbents up to field capacity. Such a barrier blocks HC migration into lower soil layers and groundwater, but remains permeable for water. The efficient immobilization of hydrophobic contaminants by means of sorption-capillary barriers is achieved owing to three simultaneous effects: • increase of hydraulic resistance of water-saturated soil media towards HC filtration due to the mineral sorbents inserted into the soil • increase of swelling properties of inserted sorbents in moistened environment • enhancing soil/subsoil sorption capacity towards hydrophobic contaminants as a result of inserting organic materials into the moistened soil 17

  18. Water Water Comparison of hydrophobic anti-filtration screens (barriers) for soil and groundwater protection Impervious barrier (polymers, cross-linked polymer foam, suspensions, hydraulic barriers) Cost of technology: 25.000-100.000 $/ha (only reagents w/o injection wells boring) +100.000 $/ha(100 wells) Isolation barrier (clay, bentonite geotextile, geomembranes, polymer films, concrete base) Cost of technology: bentonite geotextile - 100.000 $/ha, geomembrane – from 50.000 $/ha, concrete – 50-100 $/m3 (from 100.000 $/ha) (only materials w/o soil treatment) +3.000 $/ha(soil treatment arrangements) Sorption-capillary barrier (hydrophilic matter) Cost of technology: from 5.000 $/ha (full charge including reagents, soil treatment and wages) Cost of materials: zeolite mineral – 2.000 $/ha, peat – 3.000 $/ha, tree bark – 11.000 $/ha, rubber crumb – 7.000 $/ha 18

  19. The schemes of addition of sorbents to the soil 1 – Soil 2 – Mixture of mineral sorbent (zeolite, clay, diatomite) with soil 3 – Moistening to field capacity 4 – Organic sorbent (peat, sawdust, bark, cellulose, rubber crumb) (a) only mineral sorbents are inserted into the upper (h = 25 cm) layer (2) of soil (1) as a mixture with initial soil (b) the layer of an organic sorbent (4) (h = 5-20 cm) is placed under the top soil layer (1) (c) the combined scheme, where the upper layer is formed from the mixture of a mineral sorbent with soil (2) and a layer of an organic sorbent (4). - After inserting sorbents, soil is moistened (3) up to the field capacity 19

  20. Practical approval of the technology in the stationary lysimetric complex of Kazan State University • The application of schemes (a) and (b) is sufficient for full retention of liquid HC in the 0-25 cm layer of middle and heavy loamy soils. • In case of the light (sandy loam) soil this effect is reached by usage of scheme (c)of elaborated technology 20

  21. Practical implementation Unequipped site Site with protective barrier The developed technology of soil and groundwater protection from HC contamination is applicable to the areas of the raised environmental risk, such as locations of petroleum and fuel storages, pipelines and gasoline stations, etc. The advantages: • high performance of HC retention in the upper soil layers • maintenance of good soil water-physical properties • low cost and environmental safety owing to using cheap and environmental-friendly materials and low expenditures for the implementation of the technology. 21

  22. Patents Patent of Russian Federation No. 2361042 “Method of protection of soils and ground water against contamination by oil and oil products” Database certificate of Russian Federation No. 10020 “Isotherms of vapor-phase sorption of organic compounds on geosorbents and optimal parameters of approximating equations” 22

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