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VERSITy MARCH 2014 UNI PEDER MARIBO BT-SOIL SOIL CONTAMINANTS: TRANSPORT & SPREADING
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TRANSPORT & SPREADING PEDER MARIBO MARCH 2014 FROM LAST: DEGRADATION › (Heavy metals: not degraded.) › Organic chemicals (C x H y ) – factors: pH, temp (Q-10), adaptation (history),.. Redox environment: O 2, NO 3, Fe(III), SO 4 … Cl (I, Br), molecule structure (aromatics)… › 0.order: dC/dt = k › 1.order: (co-metabolic) dC/dt = k·C › (Monod…)
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TRANSPORT & SPREADING PEDER MARIBO MARCH 2014 PLAN THE 20/3 › Assignment 4 review › Basic transport / spreading mechanism: diffusion, dispersion, advection. › Transport to indoor climate Assignment 6a › Retardation Assignment 6b & 6c
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TRANSPORT & SPREADING PEDER MARIBO MARCH 2014 TRANSPORT IN SOIL WATER AND AIR › Diffusion › Dispersion › Advection/convection __________________ › Retardation
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TRANSPORT & SPREADING PEDER MARIBO MARCH 2014 http://www.youtube.com/watch?v=VY0mZUDvbH4
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TRANSPORT & SPREADING PEDER MARIBO MARCH 2014 Darcy: V = -K·dH/dX POROUS MEDIA CONVECTION Soil- water:
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TRANSPORT & SPREADING PEDER MARIBO MARCH 2014 DIFFUSIVE CONTRIBUTION, AIR: (for one layer with thickness x) V L = relative fraction of air in media (V air /(V total ). Also called air-filled portosity D L = Diffusion constant for the chemical in air [m 2 /s] n = media porosity. Range: [0 - 0.4] C = concentration (on either side of porous layer) X = thickness of porous layer [m]
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TRANSPORT & SPREADING PEDER MARIBO MARCH 2014 EXAMPLE › Transport & risk assessment 8
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TRANSPORT & SPREADING PEDER MARIBO MARCH 2014 INDOOR CLIMATE CONTRIBUTION › Diffusion through porous layers › Convection through cracks and openings
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TRANSPORT & SPREADING PEDER MARIBO MARCH 2014 CRACKS…& CONVECTION J: flux [mg/m 2 ·s] η : dynamic viscosity for the gas [kg/(m·s)] w: width of cracks [m]A: area [m 2 ] C u : gas concentration under floor [mg/m 3 ] l: thickness of floor [m]∆P: pressure difference over floor [Pa] For more details refer to appendix 5.3 & 5.4 in EPA guidelines 7/2002.
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TRANSPORT & SPREADING PEDER MARIBO MARCH 2014 MEASUREMENTS › ADT / AC tubes OBS: Air exchange rate Time of year Groundwater level Wind & temperature Ambient pressure Available airspace
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TRANSPORT & SPREADING PEDER MARIBO MARCH 2014 PAY ATTENTION TO:
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TRANSPORT & SPREADING PEDER MARIBO MARCH 2014 REMEDIATION? More on this later…
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