Managed Aquifer Recharge (MAR) has been increasingly recognized as a sustainable groundwater management strategy, but its operational sustainability is often constrained by clogging. This study evaluated clogging mechanisms at a field-scale MAR test site in Hongseong, Korea, by integrating injection tests, physicochemical analyses, thermodynamic modeling, and mineralogical characterization. During approximately 2.7 months of injection, injectivity remained generally stable and no severe clogging was observed, although partial declines occurred under prolonged quasi-steady conditions. Pre-treatment of recharge water substantially improved the Modified Fouling Index from 104.4 to 18.3 s/L 2 , yielding clogging velocities of 0.007–0.039 m/year near the well screen, indicative of slow clogging progression. Turbidity and fine particles (1–3 μm) were markedly reduced by pre-treatment, though localized mobilization of fines occurred in coarser sediments. Concentrations of Na + , K + , Cl − , and HCO 3 − decreased due to dilution, whereas and NO 3 − temporarily increased from nitrate input before declining through denitrification. SAR values (≤ 0.82) and sodium percentages (≤ 35.7%) indicated negligible risks of clay swelling or dispersion. Thermodynamic analyses revealed persistent supersaturation of Fe oxides, but low dissolved Fe concentrations limited actual precipitation. Mineralogical analysis for soil samples showed little change in clay-rich SS1, whereas SS2 exhibited pronounced alteration of biotite to secondary clays, pore reduction, and particle mobilization. Comparison of field observations with physicochemical and mineralogical predictions highlighted the complementary strengths and limitations of each approach. Overall, clogging was limited and largely mitigated by pre-treatment, though long-term risks associated with geochemical shifts and mineral alteration remain.
Kim et al. (Wed,) studied this question.