Transport and degradation of CFC gases in the saturated and unsaturated zone

  • Jensen, Karsten Høgh (Project Manager)
  • Engesgaard, Peter Knudegaard (Project Participant)
  • Højberg, Anker Lajer (Project Participant)

    Project Details

    Description

    The outlet rate of CFC gases to the atmosphere has continuously increased since the initial outlet (1930's-1940's) up to the early 90's. The increasing atmospheric concentration and the fact that CFC gases are soluble in water make it possible to use these gases for groundwater age dating, provided they are inert in the groundwater environment. By using numerical transport codes the dominant transport mechanisms were investigated for a sandy aquifer, Rabis Creek, from which several concentration profiles of CFC-11 (CCl3F), CFC-12 (CCl2F2) and CFC-113 (C2Cl3F3) have been measured. The saturated zone at the site is characterized by an upper aerobic and a lower anaerobic zone. For the lower zone a satisfying match between observed and simulated concentrations could only be obtained if degradation was included in the numerical simulations
    StatusFinished
    Effective start/end date01/09/199631/03/1997