Characterisation and quantification of physical and geochemical processes during the artificial recharge of a heterogeneous, low carbonate aquifer

This study provides a comprehensive analysis of the geochemical and Isotopic changes during managed aquifer recharge within a physically and geochemically heterogeneous aquifer. Numerical modelling was employed to quantify the coupled solute/heat transport and geochemical processes and to elucidate the controls on the spatial land temporal evolution of solutes and stable isotopes. Pyrite oxidation and associated pH buffering were Identified as the most Important geochemical processes to drive the water quality changes that occurred during the subsurface passage and storage of the injected water. Buffering reactions were shown to vary with depth as a function of the depositional environment.