생태융합환경공학연구실

Antibiotic- resistant bacteria (ARB) and antibiotic resistance genes (ARGs) persist in wastewater as chemically stable contami nants that evade conventional treatment, driving a global health crisis. Photocatalysis offers a promising route to simultaneously inactivate ARB and degrade ARGs. However, its practical implementation stays hindered by fundamental gaps in understanding how material interfaces control their fate. This review critically analyzes the interfacial battlefield, where surface chemistry, charge dynamics, and nanoconfinement determine the efficiency and mechanism of resistance destruction. We establish a quan titative reaction–diffusion framework that reveals why photocatalytic degradation is governed not by bulk- phase kinetics but by coupled transport–adsorption–reaction processes at the nanoscale interface. Through Damköhler analysis, we demonstrate that short- lived reactive oxygen species (ROS, ●OH diffusion < 10 nm) impose transport- limited regimes where adsorption and nano confinement become as critical as charge separation. We evaluate the dual target challenge: ARB as complex, multi- layered cellu lar structures requiring membrane disruption, and ARGs as persistent polyelectrolytes demanding complete mineralization. By examining how ROS with distinct lifetimes and diffusion distances operate at material interfaces, we establish that adsorption and nanoconfinement are as critical as charge separation. The review synthesizes recent advances in doping, heterojunction engineering (Z- scheme, S- scheme), defect creation, and carbon- based mediators through the cohesive perspective of interfacial design. Key gaps include unverified eARG mineralization, matrix scavenging, catalyst fouling and regeneration, biofilm and dormant cell formation after sublethal treatment, and insufficient life assessment. A roadmap is proposed toward selective, re generable, matrix- tolerant and sustainability guided photocatalytic systems for antibiotic- resistance control.

Per- and polyfluoroalkyl substances (PFAS) pollution in South Korean water systems is emerging environmental and public health concern, yet nationwide assessments remain limited. This review systematic evaluates PFAS occurrence across South Korea's primary water bodies and wastewater treatment plants (WWTPs), integrating historical and recent datasets from 49 facilities. Surface water monitoring (2004-2006) revealed widespread contamination, with 1.3-45.2 ng/L for PFOS and 2.9-19.7 ng/L for PFOA, particularly in the Hangang and Nakdonggang rivers, where downstream gradients reached ~40 ng/L (PFOA) and 38-59 ng/L (PFOS). Temporal analysis demonstrated a compositional shift from legacy long-chain PFAS (2006) to short-chain alternatives (2023-2024), reflecting regulatory-driven industrial transitions. WWTP analysis (2010) revealed industrial facilities consistently exceeded domestic counterparts, with PFOS reaching 829.44 ± 1837.41 ng/L in electronics manufacturing, of which data, collected in 2010, may not fully reflect the current situation. Conventional treatment proved ineffective, as effluent concentrations being 84-191% of influent levels. Current South Korean guidelines list only some PFAS as monitoring substances, with outdated values (70 ng/L for PFOA and PFOS) compared to stricter global standards. These findings highlight widespread PFAS detection and a critical regulatory gap, underscoring the urgent need for enforceable standards and advanced treatment technologies to support effective PFAS management.

This study investigated the performance of calcium polysulfide (CPS) for immobilizing mixed heavy metals in
acidic–oxidizing groundwater collected from a smelting-impacted refinery in South Korea. A laboratory column
experiment was conducted using site-specific soil and groundwater to evaluate CPS transport, redox evolution,
metal precipitation, and hydraulic response under realistic geochemical conditions. The injection of CPS rapidly
established reducing and alkaline environments, promoting the precipitation of metal sulfides (MeS(s)), gypsum,
and secondary iron (hydr)oxides while inducing only moderate reductions in hydraulic conductivity. Massbalance
analyses demonstrated nearly complete cadmium sequestration and partial removal of zinc and magnesium,
governed primarily by sulfide affinity and solubility equilibria. Mineralogical and spectroscopic characterization
confirmed the formation of ZnS(s), CdS(s), and CaSO4⋅2H2O(s), whereas microbial community
profiling revealed enrichment of sulfur- and iron-metabolizing taxa within CPS-reactive zones, suggesting potential
microbial contributions to long-term stability. Compared with previous tests employing clean model
sands, the overall removal efficiency in site soil was lower, reflecting the effects of geochemical complexity,
competing ions, and localized precipitation. These findings demonstrate that the efficiency and longevity of CPS
treatment are controlled by the interplay among metal-specific thermodynamics, site mineralogy, and redox
buffering. The results highlight the importance of integrating mass-balance evaluation, mineralogical confirmation,
and microbial characterization to accurately assess in-situ performance and to optimize design parameters
for sustained sulfide-based remediation of mixed-metal contaminated groundwater.

This study investigated the inhibition potential and repeated-use stability of a functional zeolite medium in which quaternary ammonium compounds (QACs) were immobilized on the zeolite surface through a Sol-Gel process. The prepared QACs-coated Zeolite was applied to Microcystis aeruginosa (M. aeruginosa) under laboratory-scale conditions, and its performance was evaluated based on visual changes, chlorophyll-a (Chl-a), phycocyanin (PC), pH, pseudo-first-order decay constants (k), surface characterization (SEM, EDS, and FT-IR), TOC-based leaching assessment, and microcystin analysis. The results showed that the QACs-coated Zeolite treatment promoted visible discoloration of the suspension. Compared with uncoated zeolite and sodium silicate-coated zeolite, the QACs-coated Zeolite induced greater reductions in both Chl-a and PC, with PC showing a more sensitive response. The pseudo-first-order decay analysis also indicated that the apparent pigment decay rate increased with increasing QACs coating concentration. In repeated-use experiments using the same medium for three consecutive cycles, similar trends were maintained, suggesting that the material retained a certain level of reactivity under repeated-use conditions. SEM, EDS, and FT-IR analyses suggested the formation of an organic-inorganic composite coating layer on the zeolite surface. TOC-based indirect estimation showed that Sol-Gel-coated samples exhibited lower leaching tendencies than the simply impregnated sample, implying that the Sol-Gel network may suppress the release of QACs into water to some extent. In addition, six major microcystin congeners were below the detection limit in all treatment conditions. Overall, the QACs-coated Zeolite showed the potential to induce pigment reduction, flocculation, and sedimentation of M. aeruginosa, while maintaining a certain degree of reactivity during repeated use. The Sol-Gel immobilization approach also appeared advantageous over simple impregnation in terms of leaching stability. However, because this study mainly relied on pigment-based indicators and qualitative observations, further studies are needed to evaluate cell viability, toxin partitioning, direct QACs quantification, ecotoxicological safety, and field-scale applicability.

This study investigated the mineral carbonation and neutralization behavior of red mud (RM) using CO₂ microbubbles (CO₂ MBs) under ambient temperature and pressure conditions, and further assessed the feasibility of utilizing carbonated RM as a cement substitute. Batch experiments were conducted at various solid-to-liquid ratios (S/L = 0.001–1.0), monitoring pH, electrical conductivity (EC), and aqueous carbonic acid (H₂CO₃(_aq)) concentrations. In the RM–CO₂ MBs system, pH initially dropped sharply and then recovered to the buffering zone (pH 7–8.5), while EC exhibited a rapid rise followed by gradual decline, indicating sequential ion release and carbonate precipitation. The H₂CO₃(_aq) concentration decreased over time due to both carbonation consumption and pH-induced speciation shift. In continuous experiments (reactor dimensions: D = 14.6 cm, H = 34 cm, S/L = 0.025), both powdered (RM-P) and sludge-type (RM-S) samples achieved neutralization (pH = 7) within 4 minutes, accompanied by a characteristic EC decrease–rebound pattern. The total inorganic carbon (TIC)-based CO₂ uptake of RM-S reached 8.87 g-CO₂/kg-RM, corresponding to approximately 84% of the theoretical maximum carbonation potential (TMCP). Mortar specimens incorporating carbonated RM as a partial cement replacement (0–15 wt%) exhibited decreasing compressive strength with increasing substitution ratio, yet 5 wt% replacement maintained adequate strength for non-structural construction materials. These results demonstrate that CO₂ MBs enable rapid (≤2 min), high-efficiency carbonation and neutralization of RM under ambient conditions without pressurized systems. The proposed process provides a low-energy, environmentally friendly pathway for simultaneous CO₂ sequestration and red mud valorization, contributing to sustainable carbon-neutral technology.

Uncertainties in climate change and precipitation patterns reduce the predictability of groundwater and surface watermanagement. In the process of constructing groundwater flow models for existing groundwater management, large-scalewatersheds are typically the primary focus. However, in watershed environments with complex boundary conditionswhere coastal lagoons and rivers coexist, it is necessary to establish conditions distinct from those of large-scalewatersheds. This study, targeting the Songji lagoon watershed on the east coast, determined that defining boundaryconditions in small-scale basins can significantly influence the predictive stability of the model and the results ofsensitivity analysis. It quantitatively investigated the impact of boundary condition settings on the calibration andpredictive accuracy of groundwater flow models. To this end, nine scenarios were constructed by stepwise combination ofhydraulic conductivity, river, lake, and drainage conditions. Steady-state simulations using MODFLOW and parametercalibration based on PEST were performed to simulate groundwater flow for each scenario. Analysis results indicated thatthe scenario employing a stepwise calibration method, where river and lake water levels (stage) and conductance were setfirst, yielded the most effective water level prediction accuracy (R2 = 0.998 and RMSE = 0.138). This demonstrates that,in small coastal basins, a boundary-focused calibration strategy is an effective approach that reduces spatial uncertaintyand enhances model reliability compared to traditional parameter calibration.