Symulacja rozkładów ciśnień i prędkości przepływu powietrza w procesie desorpcji próżniowej zanieczyszczeń z gruntu

• Autorzy: Kawala Z. , Dakiniewicz P. , Czerniak H. , Araszkiewicz M.

Warianty tytułu

EN

Computer simulation of pressure distributions and air flow rates in the process of soil vapor extraction

• Języki publikacji: PL

Abstrakty

EN

Soil and groundwater contamination by petroleum hydrocarbons and organic solvents has become a worldwide problem, which primarily faces high-technology countries. Soil vapor extraction (SVE) of volatile and some semivolatile compounds is rapidly being recognized as a technically and economically sound alternative to the available methods of cleaning chemically polluted soils. SVE entails the induction of an advective air phase through the contaminated vadose zone of the soil. In the unsaturated zone, the air flow can be established with combinations of withdrawal (extraction) and injection (if required) wells. Air laden with the contaminant vapors moves along the induced flow paths toward the withdrawing system, where it is subject to after-treatment. If the process is carried out for a sufficiently long time, it will be possible to remove all of the contaminants from the soil. The use of the SVE method provides continuous air flow through the vadose zone, which is a requisite for an efficient cleaning operation. A reliable assessment of the pressure distributions in the vicinity of the extraction wells, and a thorough analysis of the air flow conditions are of great importance to the design of an optimal SVE system, as well as to the determination of the major operating parameters. The present paper describes a three dimensional mathematical model which predicts the steady-state air flow through the unsaturated zone of the soil. The paper also includes the results of a computer simulation of air flow in soils, using the AIR3D software developed by loss and Baehr. With this software it was possible to examine how the properties of the soil (porosity, permeability and anisotropy) and the operating parameters of the SVE system (number and arrangement of the wells, depth and length of the filters, vacuum head in the wells) affect the pressure distribution, the mass and volumetric air flow rate, as well as the components of the air velocity vector in the soil.

Słowa kluczowe

PL

zanieczyszczenia gruntów; zanieczyszczenia wód; zanieczyszczenia ropopochodne; rozpuszczalniki organiczne; usuwanie zanieczyszczeń; desorpcja próżniowa; przepływ powietrza gruntowego; model matematyczny

• Wydawca: Polskie Zrzeszenie Inżynierów i Techników Sanitarnych, Oddział Dolnośląski
• Czasopismo: Ochrona Środowiska
• Rocznik: 2002
• Tom: nr 3
• Strony: 15--21
• Opis fizyczny: Bibliogr. 12 poz., rys., tab.

Twórcy

autor

Kawala Z.

• Instytut Inżynierii Chemicznej i Urządzeń Cieplnych, Politechnika Wrocławska, ul. C. K. Norwida 4/6, 50-373 Wrocław

autor

Dakiniewicz P.

• Instytut Inżynierii Chemicznej i Urządzeń Cieplnych, Politechnika Wrocławska, ul. C. K. Norwida 4/6, 50-373 Wrocław

autor

Czerniak H.

• Instytut Inżynierii Chemicznej i Urządzeń Cieplnych, Politechnika Wrocławska, ul. C. K. Norwida 4/6, 50-373 Wrocław

autor

Araszkiewicz M.

• Instytut Inżynierii Chemicznej i Urządzeń Cieplnych, Politechnika Wrocławska, ul. C. K. Norwida 4/6, 50-373 Wrocław

Bibliografia

• 1. J. S. CHO, D. C. DIGULIO: The simulation of air flow in soil vacuum extraction system by 3D ground water flow model. Conference of Hazardous Waste Research Proceedings, Kansas State University, Manhattan 1990, pp. 621-635.
• 2. D. WILSON: Modelling of In-Situ Techniques for Treatment of Contaminated Soils. Technomic Publishing Company, 1995.
• 3. G. FURDYN, Z. KAWAŁA: Odnowa zanieczyszczonych gruntów metodami in-situ. Ochrona Środowiska, 1996, nr 2(61), ss. 27-34.
• 4. Z. KAWAŁA, T. ATAMAŃCZUK: Zastosowanie prądów wysokiej częstotliwości i mikrofal do oczyszczania gruntów z substancji ropopochodnych. Ochrona Środowiska, 1998, nr 1(68), ss. 43-47.
• 5. D. L. JORDAN, J. W. MERCER, R. M. COHEN: Review of mathematical modeling for evaluating soil vapor extraction system. Raport EPA/540/R-95/513, Ohio 1995.
• 6. W. P. BEAHR, M. F. HULT: Evaluation of unsaturated zone air permeability through pneumatic tests. Water Res., 1991, Vol. 27, pp. 2605-2617.
• 7. G. FURDYN, Z. KAWAŁA: Symulacja przepływu powietrza w gruncie podczas oczyszczania skażonego terenu. Mat. konf. „Współczesne problemy hydrologii”, Kiekrz 1997, ss. 283-286.
• 8. M. SEPEHR, Z. A. SAMANI: In situ soil remediation using vapor extraction wells, development and testing of a three-dimensional finite-difference model. Ground Water, 1993, Vol. 31, PP- 425-436.
• 9. P. C. JOHNSON, M. W. KEMBLOWSKI: Quantitative analysis for the cleanup of hydrocarbon-contaminated soils by in-situ soil venting. Ground Water, 1990, Vol. 28(3), pp. 413-429.
• 10. S. CHAO, R. W. FALTA, 1. JAVANDEL: Analytical solution for steady State gas flow to a soil vapor extraction well. Water Res., 1992, Vol. 28, pp. 1105-1120.
• 11. J. S. CHO: A three-dimensional air flow model for soil venting: superposition of analytical functions. Journal Hazard. Mat., 1993, Vol. 35, pp. 31-51.
• 12. C. J. JOSS, A. L. BEAHR: Documentation of AIR3D, an adaptation of the ground-water flow code modflow to simulate three-dimensional air flow in unsaturated zone. U.S. Geological Survey Open-File Report 94-533, West Trenton 1995.