miniRUEDI used to quantify air-water gas exchange in surface waters – without adding tracer gases!

In their recent paper “A Novel Approach To Quantify Air–Water Gas Exchange in Shallow Surface Waters Using High-Resolution Time Series of Dissolved Atmospheric Gases“, Uli Weber and his colleagues developed a new method to study and quantify the air-water gas exchange in a shallow surface waters. The method uses a miniRUEDI to quantify the natural variations of dissolved atmospheric gases in the water. The resulting high-resolution time series of dissolved gas concentrations in the water yield accurate gas exchange rates without adding artificial tracers.

miniRUEDI used for gas monitoring in a full-scale experiment targeted at underground radioactive waste disposal

In their recent paper “On-line monitoring of the gas composition in the full-scale emplacement experiment at Mont Terri (Switzerland)“, Yama Tomonaga and his colleagues at Nagra, Eawag and ETH Zurich used a miniRUEDI to study the dynamics and the fate of the gas species in a tunnel of a full-scale experiment targeted at radioactive waste disposal in Switzerland.

Highlights:

  • An on-line gas monitoring has been implemented for the FE experiment at Mont Terri underground rock laboratory.
  • The monitoring of gas species was performed successfully over several months.
  • Rapid gas exchange occurs between drift backfilling and FE niche/host rock.
  • Terrigenic gases (e.g., 4He, 40Ar, CH4, CO2) accumulated in the backfill pore space.
  • Fast gas exchange partly explains the O2 removal from the backfill pore space.

Use of miniRUEDI Instruments in Air/Water Exchange Studies in Small Streams

In their recent paper “In-situ mass spectrometry improves the estimation of stream reaeration from gas-tracer tests“, Julia Knapp and her colleagues at Uni Tübingen and Eawag used two miniRUEDI instruments to study air/water exchange in small streams.

Highlights:

  • Determination of gas-exchange rates in streams from gas-tracer testsQuantification of gas tracers using a portable gas-equilibrium mass spectrometer
  • Reliable estimation of reaeration rates from krypton and propane injections
  • In-situ analysis avoids gas loss and improves the determination of reaeration rates