Université de Neuchâtel

Comments on “Analytical modelling of fringe and core biodegradation in groundwater plumes.” by Gutierrez-Neri et al. in J. Contam. Hydrol. 107: 1–9

Hunkeler, Daniel ; Höhener, P ; Atteia, O

In: Journal of Contaminant Hydrology, 2010, vol. 117, p. 1-6

In this comment, we revisit equations concerning the analytical solutions presented by Gutierrez-Neri and co-workers for reactive transport for a pollutant undergoing core and fringe degradations. We state that a correction needs to be made in Eq. (9) of the work of Gutierrez- Neri et al. in order that the equation follows closely previous work published by J. Bear (in 1-D) and P.A. Domenico (in...

Université de Neuchâtel

Engineered and subsequent intrinsic in situ bioremediation of a diesel fuel contaminated aquifer

Hunkeler, Daniel ; Höhener, P ; Zeyer, J

In: Journal of Contaminant Hydrology, 2002, vol. 59, p. 231-245

A diesel fuel contaminated aquifer in Menziken, Switzerland was treated for 4.5 years by injecting aerated groundwater, supplemented with KNO3 and NH4H2PO4 to stimulate indigenous populations of petroleum hydrocarbon (PHC) degrading microorganisms. After dissolved PHC concentrations had stabilized at a low level, engineered in situ bioremediation was...

Université de Neuchâtel

Documentation of time-scales for onset of natural attenuation in an aquifer treated by a crude-oil recovery system

Ponsin, V ; Maier, J ; Guelorget, Y ; Hunkeler, Daniel ; Bouchard, D ; Villavicencio, H ; Höhener, P

In: Science of the Total Environment, 2015, vol. 512-513, p. 62-73

A pipeline transporting crude-oil broke in a nature reserve in 2009 and spilled 5100 m3 of oil that partly reached the aquifer and formed progressively a floating oil lens. Groundwater monitoring started immediately after the spill and crude-oil recovery by dual pump-and-skim technology was operated after oil lens formation. This study aimed at documenting the implementation of...

Université de Neuchâtel

Engineered in situ bioremediation of a petroleum hydrocarbon-contaminated aquifer : assessment of mineralization based on alkalinity, inorganic carbon and stable carbon isotope balances

Hunkeler, Daniel ; Höhener, P ; Bernasconi, S ; Zeyer, J

In: Journal of Contaminant Hydrology, 1999, vol. 37, no. 3-4, p. 201-223

A concept is proposed to assess in situ petroleum hydrocarbon mineralization by combining data on oxidant consumption, production of reduced species, CH4, alkalinity and dissolved inorganic carbon (DIC) with measurements of stable isotope ratios. The concept was applied to a diesel fuel contaminated aquifer in Menziken, Switzerland, which was treated by engineered in situ...

Université de Neuchâtel

Petroleum hydrocarbon mineralization in anaerobic laboratory aquifer columns

Hunkeler, Daniel ; Jörger, D ; Häberli, K ; Höhener, P ; Zeyer, J

In: Journal of Contaminant Hydrology, 1998, vol. 32, no. 1-2, p. 41-61

The anaerobic biodegradation of hydrocarbons at mineral oil contaminated sites has gathered increasing interest as a naturally occurring remediation process. The aim of this study was to investigate biodegradation of hydrocarbons in laboratory aquifer columns in the absence of O2 and NOۙ, and to calculate a mass balance of the anaerobic biodegradation processes. The...

Université de Neuchâtel

222Rn as a Partitioning Tracer To Detect Diesel Fuel Contamination in Aquifers : Laboratory Study and Field Observations

Hunkeler, Daniel ; Hoehn, E ; Höhener, P ; Zeyer, J

In: Environmental Science & Technology, 1997, vol. 31, no. 11, p. 3180-3187

The use of 222Rn, a naturally occurring radioactive isotope, was investigated as a partitioning tracer to detect and quantify the amount of non-aqueous-phase liquids (NAPLs) in contaminated aquifers. Diesel fuel was chosen as a model NAPL. The diesel fuel-water partition coefficient for 222Rn was 40 ± 2.3, in bottles containing diesel fuel and water at 12 °C. In...

Université de Neuchâtel

Bioremediation of a diesel fuel contaminated aquifer : simulation studies in laboratory aquifer columns

Hess, A ; Höhener, P ; Hunkeler, Daniel ; Zeyer, J

In: Journal of Contaminant Hydrology, 1996, vol. 23, p. 329-345

The in situ bioremediation of aquifers contaminated with petroleum hydrocarbons is commonly based on the infiltration of groundwater supplemented with oxidants (e.g., O2, NO ‾3) and nutrients (e.g., NH+4, PO34‾). These additions stimulate the microbial activity in the aquifer and several field studies describing the...

Université de Neuchâtel

Analytical modelling of stable isotope fractionation of volatile organic compounds in the unsaturated zone

Bouchard, Daniel ; Cornaton, Fabien ; Höhener, P ; Hunkeler, Daniel

In: Journal of Contaminant Hydrology, 2011, vol. 119, p. 44-54

Analytical models were developed that simulate stable isotope ratios of volatile organic compounds (VOCs) near a point source contamination in the unsaturated zone. The models describe diffusive transport of VOCs, biodegradation and source ageing. The mass transport is governed by Fick's law for diffusion. The equation for reactive transport of VOCs in the soil gas phase was solved for different...

Université de Neuchâtel

Intrinsic bioremediation of a petroleum hydrocarbon-contaminated aquifer and assessment of mineralization based on stable carbon isotopes

Bolliger, C ; Höhener, P ; Hunkeler, Daniel ; Häberli, K ; Zeyer, J

In: Biodegradation, 1999, vol. 10, p. 201-217

This study presents a stepwise concept to assess the in situ microbial mineralization of petroleum hydrocarbons (PHC) in aquifers. A new graphical method based on stable carbon isotope ratios (δ13C) was developed to verify the origin of dissolved inorganic carbon (DIC). The concept and the isotope method were applied to an aquifer in Studen, Switzerland, in which more than 34,000...