Flinders University - ATES and contaminated groundwater
1. EFFECTS OF AQUIFER THERMAL ENERGY STORAGE (ATES) ON MOBILE CONTAMINANTS IN A GROUNDWATER SYSTEM: A MODEL APPROACH Koen Zuurbier (KWR, VU, Deltares), Niels Hartog (Deltares), Johan Valstar (Deltares), Boris van Breukelen (VU), Vincent Post (VU) 26.11.2010, Flinders, Australia
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4. 2. Background: ATES and mobile contaminants IF Technology Doublet Summer Winter
5. 2. Background: ATES and mobile contaminants ATES ≠ Geothermal Energy! Heat & cold demand Heat demand Building = supply+user Building = user
6. 2. Background: ATES and mobile contaminants BTES (Borehole Thermal Energy Storage): Closed loop systems Horizontal Vertical
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15. 2. Background: ATES and mobile contaminants How to describe degradation: Monod kinetics: combination of 0 th and 1 st -order Not modelled (yet) At high C At low C
16. 3. Methods: modelling tools No integral modelling code available Flow: MODFLOW Transport: MT3DMS Density/Viscosity + SEAWAT (V4) Reactions: PHT3D (V2) (PHREEQC) Plume blending: Multi-Node-Well Package (MODFLOW) (total discharge discharge per model layer) (mixing concentrations in well) Compilation
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18. 4. Case study ‘Uithof’ You are here Temp injection = 8 o C / 16 o C Temp background = 10,5 o C Imbalance: net 1.2 % to K1
19. 4. Case study ‘Uithof’ You are here Temp injection = 8 o C / 16 o C Temp background = 10,5 o C Imbalance: net 1.2 % to K1 N.B.: Start installation in last week of November (week 1)
20. 4. Case study ‘Uithof’ 2.8 m 50 m 56 m 41 m Vertical Cross-section 39 m 1760 m 135 m Holocene cover Aquif. 1A Sandy clay Aquif. 1B Aquitard Aquif. 2 DNAPL Holocene cover Aquif. 1A Sandy clay Aquif. 1B Aquitard Aquif. 2
21. 4. Case study ‘Uithof’ Scenario’s Here: degradation using 0 th –order (1.1*10 -9 mol L -1 d -1 ) ? x x x All factors present S-4 Increasing mass in aquifer, large volume contaminated x x Degradation absent S-3 Initial increase in volume, followed by decrease (increased degr.+blending) x x DNAPL absent S-2 Contaminated plume in +/- original size x Reference: No DNAPL, no ATES S-1 Predicted effect DNAPL ATES Degr. Characteristics Scenario