The concentration and flux of organic carbon in aquifers is influenced by recharge and ion, and surface and subsurface processing. In this study groundwater was ed from a shallow fractured rock aquifer and dissolved organic carbon (DOC) was measured in observation bores at different distances from the ion bore. Groundwater ion at rates exceeding the aquifers yield resulted in increased DOC concentration up to 3,500 percent of initial concentrations. Potential sources of this increased DOC were determined using optical fluorescence and absorbance analysis. Groundwater fluorescent dissolved organic material (FDOM) were found to be a combination of terrestrial-derived humic material and microbial or protein sourced material. Relative molecular weight of FDOM within four metres of the ion well increased during the experiment, while the relative molecular weight of FDOM between four and ten metres from the ion well decreased. When the aquifer is not being pumped, DOC mobilisation in the aquifer is low. We hypothesise that the physical shear stress on aquifer materials caused by intense ion significantly increases the temporary release of DOC from sloughing of biofilms and release of otherwise bound colloidal and sedimentary organic carbon (SOC).
展开▼
