4 major challenges in the source zone!!! Source Zone Remediation with innovative Technologies. Very large reductions wanted/needed

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1 Source zone & plumes Source Zone Remediation with innovative Technologies Tom Heron Geologist & Head of Department Stockholm Aalborg Århus Esbjerg København Odense Poznan Warszwa Krakóv Helsinki Sofia Kiév 95 employees 25 Environmental specialists Source zone Volatile/semi-volatile contaminants: Oil products, chlorinated solvents etc. > % of the total mass Relatively small volume High soil concentrations Mobile free phase and/or residual droplets Dissolved concentrations > 1 % of solubility Altered redox conditions The challenges of source zone remediation 4 major challenges in the source zone!!! Very large reductions wanted/needed Typical dry cleaner with PCE Pre-remedy Remedial goal (MCL) 1. µg/l 1 µg/l Variations in permeability/2-phase flow

2 The challenges of source zone remediation Flow by-pass due to contamination The challenges of source zone remediation Diffusion limitations Free phase Dissolved phase Dissolution kinetics Bio active Removal efficiency in source zones Thermal: Steam, ISTD, ERH Homogeneous sandy soil > 95 % Radical oxidation: Fentons, persulfate, Regen-Ox (Oxidation: KMnO 4 /Persulfate) What can the technologies achieve in real life? Sand 5 75% Oxidation: KMnO 4, Persulfate, ozone, H 2 O 2 (Enhanced biological degradation) (Air Sparging/SVE) Volatile/semi-volatile contaminants: Oil products, chlorinated solvents etc. < 5 % (Enhanced biological degradation) Air Sparging/SVE Free phase pumping Surfactant flushing < 25 % Pump & Treat

3 Removal efficiency in source zones Flux reduction / contamination control (NOT remediation!) Clay and silt > 95 % 5 75% < 5 % Thermal: ISTD, ERH (Radical oxidation: Fentons, persulfate, Regen-Ox etc.) Radical oxidation: Fentons, persulfate, Regen-Ox etc. Oxidation: KMnO 4, Persulfate Enhanced biological degradation Pump & Treat Passive SVE SVE Enhanced natural attenuation Enhanced reductive dehalogenation Volatile/semi-volatile contaminants: Oil products, chlorinated solvents etc. < 25 % Air Sparging/SVE Free phase pumping Surfactant flushing Pump & Treat Phytoremediation Natural attenuation Reactive permeable barriers: Zero valent Iron Oxygen diffusion In Situ Thermal Desorption Case: In Situ Thermal Desorption Chlorinated Solvents from a former Tank farm

4 ISTD: Remediation concept That s how it looks! HO Well Horizontal Vapor Collection Screen o C y Mod. To high K Steam Zone 1.8 m m Tight clay/bay mud DNAPL m R24 Insulating Vapor Cover Sand Pack In-Situ Temperatures m m m m Centroid Heater Centroi 1.8 m 1.8 m Results Average concentrations Results Maximum concentrations 35, 3, 34,222 AVG Post Remedial Goals AVG Pre 6, 51, Max Post Remedial Goals Max Pre 5, 25, Soil Concentration - ug/kg 2, 15, 1, 17, 6,65 Soil Concentration - ug/kg 4, 3, 2, 57, 5, 2, 2, 12 < RL 65 5 PCE TCE cis-1,2-dce VC Reductions: 99.96% 99.63% 99.3% 99.49% Results are based on 17 pre-treatment samples and 64 post-treatment samples. Post-treatment samples were collected from centroids (i.e., coolest locations) at random and biased depths (15 or 23% were collected between 18 and 2 ft bgs). 1, , 2, 2, 17, < RL 1,5 24 PCE TCE cis-1,2-dce VC Reductions: 99.96% 99.63% 99.3% 99.49% Results are based on 17 pre-treatment samples and 64 post-treatment samples. Post-treatment samples were collected from centroids (i.e., coolest locations) at random and biased depths (15 or 23% were collected between 18 and 2 ft bgs). 6,5 6,5

5 Project completed on time and on budget - Performance guaranteed - Remedial goals achieved Improved approach verified 8 months for construction and treatment Total TT project cost: ~$1.7M, ~ 7. yd 3 Cost of power: $35K ($.16 per kw-hr!!) Post-development value: ~$3M Case: Chemical oxidation with permanganate PCE from a dry cleaner The County of Funen Chemical oxidation Geological logs B1 B2 B3 Direct oxidation - example 4C 2 Cl 4 + 4MnO 4- +1H 2 O 3MnO 2 (s) + 6CO 2 (g) + 12Cl - + 8H + PCE Permanganate

6 Concept: Installation of KMnO 4 in clay Observed KMnO 4 : Cross section in flow direction Moraine clay with sandy zones 5 m 1 m 15 m Distance from source zone Dissolved contamination PCE diffused into matrix PCE and MnO 2 profiles in weathered clayey till Conclusions ISCO with permanganate Courtesy of Mette Broholm, TUD PCE (µg/kg) ISCO removed 3 5 % of the total mass Efficiency hampered by diffusion limitations Delivery is the key to succes -.2 Distance (m) MnO 2 (g/kgts)

7 Contaminant distribution Former dry cleaning facility Fill Case: 1, m.b.g. Steam Enhanced Extraction 1,7 m.b.g. PCE and Stoddard Solvent from a former dry cleaner 3,7 m.b.g. Sand Fillings Sand Clay The County of Northern Jutland Clay PCE Turpent. Site and treatment wells Temperature monitoring points Østerbro Aalborg Appartments Former dry cleaner K a ro line lu ndsve j Ware house Garages Shop Shed Railroad

8 Continuous steam operation after 5 days Continuous steam operation after 12 days Temperature distribution 1,5 m.b.g. Temperature distribution 1,5 m.b.g.???? >8 o C >8 o C Continuous steam operation after 28 days Continuous steam operation after 35 days Temperature distribution 1,5 m.b.g. Temperature distribution 1,5 m.b.g. >8 o C >8 o C

9 Results Extracted 9-1. kg PCE og turpentine Remaining contamination: Less than 5-8 kg When? Groundwater µ g/l Soil Vapor mg/m 3 Soil mg/kg Before remediation Max Free phase ~2.5 Free phase After remediation ,4 37 Clean-up Efficiency Remediation goal satisfied Total costs ~ appr. dkr. 2,7 mill. the@niras.dk Thank you and:????