THE USE OF LABORATORY-DETERMINED ION EXCHANGE PARAMETERS IN THE PREDICTIVE MODELLING OF FIELD-SCALE MAJOR CATION MIGRATION IN GROUNDWATER OVER A 40-YEAR PERIOD

Description of two laboratory methods for determining ion exchange parameters from intact rock column experiments from triasic sandstones. Location of the hydrogeological study area. Evolution of mineralization of groundwater between 1945 to 1980. Description of apparatus for flushing method. Values of exchange properties of intact cores : cation exchange capacity, selectivity coefficients. Modelling of field breakthrough curves is made with code PHREEQM. Discussion on fresh and saline groundwater chemistry and analysis of predicted results on some field sites wells. Interpretation of sulphate reduced estuary water and intrusion of sated water in aquifer.