Environmental water samples were systematically collected from public venues in urban and suburban districts of Shanghai from 2011 to 2020 for Legionella pneumophila (LP) surveillance. All the identified LP isolates underwent a series of testings including serotyping, pulsed field gel electrophoresis (PFGE), sequence-based typing, and antimicrobial susceptibility testing. Among 6 263 water samples, the LP-positive rate was 20.93% (1 311/6 263). The positivity rate decreased from 24.98% (287/1 149) in 2011-2012 to 20.02% (1 024/5 114) in 2013-2020 (χ2=13.92, P<0.001), with the highest monthly positivity observed from June to August (23.79%, 745/3 132). A total of 1 365 LP strains were isolated, of which 912 were further characterized, including 10 serotypes, 149 PFGE patterns, and 33 sequence types (ST). The predominant serotype was Lp1 (86.84%, 792/912), and the dominant ST was ST752 (29.50%, 269/912). ST clustering revealed two major clonal groups CG1 and CG2, accounting for 91.12% (831/912) of the isolates. The 190 LPs involved in the drug sensitivity test showed three resistance profiles: azithromycin resistance (31.05%, 59/190), ciprofloxacin resistance (0.53%, 1/190) and azithromycin+ciprofloxacin resistance (0.53%, 1/190). Azithromycin-resistant strains were predominantly ST1 (64.41%, 38/59). The antimicrobial resistance rate showed a significant decline, from 48.65% (18/37) in 2011-2012 to 28.10% (43/153) in 2013-2020 (χ2=9.38, P=0.002). In this study, compared to from 2011 to 2012, both the positivity rate and antimicrobial resistance prevalence of LP in public aqueous environments of Shanghai exhibited an overall decline from 2013 to 2020. The predominant types of LP were serotype Lp1 and sequence type ST752, with notable high-level resistance to azithromycin. Measures as enhancing the enforcement of water safety regulations and prioritizing surveillance of azithromycin resistance in LP were recommended to mitigate public health risks.

In recent years, the widespread use of antibiotics has led to their frequent detection in wastewater, while also inducing the emergence of antibiotic resistance genes (ARGs). Both are recognized as emerging contaminants and have become critical issues affecting environmental and public health. Algal-bacterial granular sludge (MBGS) technology has demonstrated high potential for efficient antibiotic removal. In this study, sulfamethoxazole (SMX), a typical sulfonamide antibiotic, was chosen as the target contaminant. Two identical sequencing batch reactors (1.4 L) were established: an experimental reactor amended with 2 g/L zero-valent iron-activated carbon (ZVI-AC) (R2) and a control reactor (R1). Both were operated for 80 cycles with synthetic municipal wastewater containing 10 µg/L SMX. The degradation mechanism of SMX was analyzed by metagenomic sequencing and molecular docking, aiming to explore the effect of ZVI-AC-enhanced MBGS system on the degradation efficiency of antibiotics and the risk of ARGs transmission. The results showed that compared with the control group, the addition of ZVI-AC promoted the chlorophyll transformation and accumulation of chlorophyll b (3.89 mg/g vs. 2.26 mg/g) in MBGS, enhanced biomass (4.06 g/L vs. 3.67 g/L) and conductivity (875.52 μs/cm vs. 830.17 μs/cm), thereby improving SMX degradation. The degradation rate constant increased from 0.0334 h⁻¹ to 0.0565 h⁻¹ (an increase of 69.2%). The effluent quality met the Grade A standard of municipal wastewater. Metagenomic analysis revealed that the addition of ZVI-AC promoted the enrichment of cytochrome P450 family genes involved in drug metabolism and reduced the generation of the harmful compound TP163 (among 9 metabolites). Molecular docking further indicated that the CYP102 enzyme (a P450 family member) exhibited enhanced binding affinity with SMX (binding energy: −8.6 kcal/mol), facilitating more efficient degradation. Specifically, the enrichment of CYP450 genes and enhanced electron transport activity drove hydroxylation and S–N bond cleavage, promoting the generation of smaller molecular metabolites. Furthermore, with the addition of ZVI-AC, the biological toxicity (inhibition rate of Escherichia coli) of system effluent was significantly reduced by 83.96 ± 10.42%. The abundance of g_Leptolyngbya (a potential host of ARGs in MBGS) markedly decreased. The abundances of ARGs (sul1, sul3) and class I integron (intI1) were reduced by 47.3%, 31.4%, and 63.3%, respectively, and 12 fewer ARG subtypes were detected, which greatly reduced the risk of horizontal transfer of ARGs. These findings indicate that the addition of ZVI-AC can facilitate the establishment of an MBGS system capable of pollutant removal, toxicity reduction, and resistance inhibition, thereby providing an engineerable technological paradigm for the efficient removal and risk control of antibiotic emerging pollutants in wastewater treatment.

Emerging micropollutants (MPs) in environmental matrices have attracted growing attention due to their adverse impacts on aquatic ecosystems. Stormwater has recently been identified as a significant source of MPs entering receiving waters, highlighting the urgent need for green stormwater infrastructure in megacities to enhance contaminant removal during stormwater harvesting and urban runoff. Biochar-based advanced oxidation processes (AOPs) have emerged as a promising solution for degrading MPs in various effluents. This study investigated the occurrence of 50 MPs—including 8 perfluorinated compounds (PFCs), 23 pharmaceuticals, 2 pesticides, 4 endocrine-disrupting chemicals, 7 nitrosamines, 2 corrosion inhibitors, and 4 preservatives—in stormwater canals and retention ponds. Concentrations ranged from 4.7 to 7,851 ng/L, with pharmaceuticals, corrosion inhibitors, PFCs, and pesticides being the most prevalent. The study further explored degradation patterns of MPs in three biochar-based hybrid systems: biochar/Fe(VI), biochar/chloramine, and biochar/persulfate. Among these, the biochar/persulfate system demonstrated the most effective overall removal, while biochar/Fe(VI) showed enhanced degradation of endocrine-disrupting chemicals, and biochar/chloramine effectively degraded amine-containing MPs. Sole biochar exhibited strong sorption capacity for PFCs, whereas biochar/persulfate moderately accelerated their degradation. Overall, this work provides comprehensive insights into the occurrence, removal efficiency, and potential risks of MPs in urban stormwater. Incorporating biochar-based AOPs into stormwater infrastructure presents a practical strategy to mitigate MP migration into receiving waters through in situ remediation.

Climate change, population growth, and urbanization have made it increasingly evident that water is no longer an unlimited or inexpensive resource. Nevertheless, public awareness of this reality remains limited. According to the Food and Agriculture Organization of the United Nations (FAO, 2021), the Republic of Korea reports a water stress level of 85.52%, classifying it as a country under severe water scarcity. The Global Commission on the Economics of Water (GCEW) also emphasized in its 2024 report The Economics of Water: A Global Common Good that systemic risks to the global water cycle directly influence economic stability and social equity. These findings underscore the need to recognize water not only as a basic necessity but also as a global common good requiring coordinated action.

Climate change has disrupted the natural hydrological cycle, posing significant threats to the reliable and safe supply of drinking water. In Korea, seasonal extremes have intensified: winters are increasingly dry, while summers are characterized by short but intense rainfall. This dual pattern creates the paradox of simultaneous droughts and urban flooding, exposing the vulnerability of existing water systems.

Seoul, as the nation’s central metropolitan city, has acknowledged these challenges. Ensuring urban water security has become a critical priority, closely linked to climate resilience. The city is advancing modernization projects that focus on rehabilitating aging pipelines, reducing leakage, and improving energy efficiency. These measures not only enhance operational reliability but also reduce costs, while aligning with the broader agenda of sustainable urban water management.

This study examines the implications of water management in the context of accelerating climate change, with a particular focus on Korea’s water resource challenges and Seoul’s policy responses. It argues that infrastructure modernization, risk reduction, and the integration of water security into climate resilience strategies are essential for sustainable urban development. By analyzing Seoul’s approach, the study offers practical insights into how metropolitan areas can strengthen resilience and safeguard water as a shared resource for future generations.

Per- and polyfluoroalkyl substances (PFASs) have been widely used across various industries due to their thermal and chemical stability. However, their resistance to degradation has led to their continuous accumulation in aquatic environments. Activated carbon (AC) is considered a practical alternative for removing PFAS. Nevertheless, coal-based activated carbon has been designated as a subject to emergency supply control, highlighting the need for the development and alternative of the materials. The key properties of PFAS adsorption using AC include electrostatic interactions, pore distribution, and surface areas. When it comes to PFAS, chain length, hydrophobicity, and functional groups are the primary factors affecting adsorption. In this study, different types of activated carbon were mixed to enhance the removal of short-chain PFASs. The initial concentration was set to 250 ng/L for each compound, reflecting the maximum concentration of individual PFAS in rivers. Three types of activated carbon—coal, coconut, and bamboo—were applied at dosage of 40 mg/L, with sufficient time of 24 hours. Binary mixtures of activated carbons (coal–coconut, coconut–bamboo, coal–bamboo) were evaluated at ratios of 1:4, 1:2, 1:1, 2:1, 4:1. Bamboo-based AC exhibited low removal efficiency about 50% for short-chains, due to strong electrostatic repulsion from its high negative zeta potential (–69.01 mV). Coconut-based AC, with a high surface area, showed PFAS removal above 85% for most PFASs. Coal-based AC demonstrated the highest adsorption capacity dominating the adsorption capacity when mixed. When only bamboo and coconut-based ACs were combined, the 1:2 ratio showed the best performance, achieving an adsorption capacity of 5.7–5.8 μg/g, comparable to that of coconut AC alone. Considering the rising demand and price of coconut AC as a substitute for coal-based AC, the combined use of bamboo and coconut AC offers a promising strategy. This approach can reduce unit costs of activated carbon and contribute to lowering operational expenses in water treatment plants.

Per- and polyfluoroalkyl substances (PFAS) are widely used in the chemical and electronic industries due to their stable structure and properties such as heat resistance and hydrophobicity, which also make them difficult to degrade and detect in aquatic environments. Activated carbon (AC) is considered one of the most effective materials for PFAS removal, however, the domestic supply of coal-based AC is entirely dependent on imports has recently been restricted due to strengthened air pollution regulations. This study aims to enhance PFAS adsorption efficiency by analyzing the carbonaceous properties and surface characteristics of bio-based AC. The surface properties of AC were Microporous coconut-AC is more likely to block pores than mesoporous AC, which interrupts the adsorption of short-chain PFAS. The highly negative zeta potential of bamboo-AC induces electrostatic repulsion with negatively charged PFAS, especially the short-chain group. Therefore, when bamboo- and coconut-AC were mixed, bamboo-AC can selectively reduced long-chain PFAS, which would otherwise adsorb onto the surface of coconut-AC and cause pore blocking. Additionally, a uniform micro- and mesopore ratio contributed to enhancing overall adsorption efficiency. The optimal mixing ratio determined from batch experiments was applied to the column test. In the early stage of column operation, short-chain PFAS were removed effectively. The short-chain compound PFBA reached breakthrough within three days, and the effluent concentration exceeded the influent’s due to displacement of PFBA by longer chain PFAS. Although PFBS has not reached breakthrough during the operation period, it is expected to be the first among PFSAs to achieve breakthrough at 58k BV. Therefore, it is necessary to develop strategies for stable PFAS removal and to continue research on activated carbon and the PFAS adsorption mechanism.

Doughnut Economics (DE) is an emerging framework for sustainability evaluation that integrates socioeconomic and biophysical spheres with theoretical bases updating traditional economic thinking. Despite an increasing number of studies on DE, a comprehensive review has yet to be undertaken. This study aims to conduct a critical systematic review following the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) principle, covering the period from 2012 to 2024 and structured around four research questions: the theoretical framework of DE and its alignment with the Sustainable Development Goals (SDGs), the publication landscape, accounting procedures, and empirical progress. The study findings indicate that: 1) DE is theoretically different from SDGs in terms of its indicator system, research foci, internal interrelationships, and sustainability assessment; 2) the UK leads in DE research, followed by USA and other European countries, with discussions in the field gaining momentum since 2021; journals like The Lancet Planetary Health and Sustainability (Switzerland) are prominent publishers on this topic; 3) selecting planetary boundaries and estimating corresponding indicators and thresholds is essential for measuring sustainability achievement by comparing actual values with these thresholds; and 4) while most countries have exceeded biophysical boundaries related to climate change and ecological/material footprints, the situation varies significantly for other boundaries like biogeochemical flows, freshwater, and land system change. Socioeconomic boundaries concerning basic human needs such as food, energy, and water are generally upheld, unlike those related to ideology and value judgments, including voice, social equity, and gender equality. DE is still in its infancy and needs further development in its theoretical and methodological framework.

This study provides methodological insights for adapting to climate crises in order to maintain urban functions in the field of waste management, where such efforts have not previously been undertaken. The purpose of this study is to develop a methodology for assessing the resilience of municipal solid waste (MSW) management to maintain normal functional performance during extreme rainfall events. The research procedure was structured as follows: 1. System structuring – defining the target waste streams and system boundaries, and establishing an evaluation framework in relation to extreme rainfall; 2. Causal loop diagram construction – identifying the impacts of heavy rainfall on MSW management functions as well as reinforcing and balancing factors; 3. Derivation of evaluation indicators – determining key factors from the causal loop diagram and extracting indicators capable of assessing these factors; 4. Application of the evaluation methodology (Anchored Min–Max Scaling, AMMS) – AMMS is an improved normalization technique that incorporates the modal interval and its midpoint to better represent typical conditions, thereby enhancing the realism of the assessment; 5. Resilience assessment – evaluating exposure, sensitivity, adaptive capacity, and their combinations. The methodology was applied to all 229 local governments in Korea, using indicator data for the year 2023. The results were visualized through map-based representations to facilitate intuitive interpretation. Based on these evaluations, spatial variations, inter-indicator differences, and regional vulnerabilities were analyzed. In addition, the study yielded important implications drawn from the evaluation results.

The escalating global deployment of wind energy, while pivotal for a cleaner future, concurrently generates a growing volume of decommissioned wind turbine blades (WTBs). These blades, inherently challenging due to their substantial size and complex composite structures, present a critical waste management dilemma; their improper disposal not only burdens landfills and risks environmental pollution but also signifies a significant waste of valuable resources that could otherwise fuel a circular economy. Addressing this urgent imperative necessitates robust collaboration and strategic alignment among key stakeholders: governments, responsible for policy and oversight; large-scale recycling companies, tasked with collection, processing, and material recovery; and remanufacturers, crucial for integrating recovered materials into new product streams. This study employs an integrated analytical framework, combining evolutionary game theory and system dynamics (SD), to comprehensively analyze the dynamic interactions, strategic choices, and evolutionary trajectories of these critical actors. Through this dual-model approach, we aim to uncover how various factors influence their propensity to adopt sustainable recycling practices and foster effective collaborative mechanisms. Our key findings reveal that appropriate and well-targeted technical subsidies for recycling technologies, coupled with direct recycling subsidies, significantly enhance stakeholder participation, driving the system towards an efficient and highly collaborative operational model. Furthermore, while initial strategy probabilities among players transiently affect the speed of system stabilization, our simulations strikingly demonstrate that all parties ultimately converge to a fully cooperative stable state (1, 1, 1), underscoring the system’s inherent self-regulating capacity when robust incentives and deterrents are in place. We also find that remanufacturers’ willingness to embrace green production practices is robustly influenced by both responsive market demand for environmentally friendly products and supportive government policies, with sustained technological advancements proving instrumental in continuously improving the economic viability of recycling and remanufacturing, thereby enhancing overall environmental outcomes. This integrated study provides valuable quantitative evidence and strategic insights for policymakers and industry leaders, offering a clear roadmap for optimizing recycling policies, designing new incentive structures, and fostering a collaborative environment that promotes the long-term sustainability of end-of-life WTB management, aligning corporate responsibility with broader environmental protection goals.

The membrane bioreactor (MBR) process is characterized by its high efficiency in contaminant removal and its broad applicability in wastewater treatment. Despite these advantages, the MBR process is still hindered by persistent challenges, particularly membrane fouling and limited phosphorus removal. Membrane fouling not only shortens the operational lifespan of the system but also increases maintenance and energy costs. In addition, the treated effluent from conventional MBRs frequently contains elevated concentrations of total phosphorus (T-P), as the system lacks a dedicated biological phosphorus removal mechanism. To overcome these limitations, novel approaches are required to enhance the stability and sustainability of MBR performance. This study introduces quorum quenching cell entrapping beads (QQ-CEB) to address membrane fouling and phosphorus removal, which are critical challenges in membrane bioreactors. An experimental investigation was conducted to evaluate the immobilized QQ-CEB. Under conditions of the immobilized QQ-CEB, the effluent total phosphorus removal was maintained at approximately 50%. In the same condition, the operational period of the system increased by approximately 2.2 times compared to conventional MBRs. Analysis of microbial products on the membrane surface revealed that their levels were reduced to approximately 28.1–47.0% respectively by QQ mechanism. Additionally, the analysis of signal molecule confirmed that the QQ mechanism mitigated biofouling by inhibiting microbial quorum sensing. The Fe³⁺ QQ-CEB demonstrated a 1.53-fold longer operational lifespan than the Ca²⁺ QQ-CEB (control). Microbial community analysis of the Fe³⁺ QQ-CEB further indicated that the internal microbial population within the media was stably maintained, while the intrusion of external microorganisms was effectively suppressed.