Abstract This study systematically characterized volatile organic compound (VOC) compositions across cuisines in China, examined how edible oils affect VOC/polycyclic aromatic hydrocarbon (PAH) emissions, and evaluated associated health risks using both deterministic and Monte Carlo probabilistic models, from which a tiered health-risk early-warning classification was derived. Results showed distinct cuisine-specific VOC profiles: high-temperature frying cuisines [barbecue (BB) and western fast food (KFC)] were dominated by alkanes, whereas cooking-wine cuisines [Hunan cuisine (XC) and western cuisine (WC)] had high alcohols (13.2%–29.2% ethanol); Sichuan cuisine (CC) showed high VOC compositional similarity with the other cuisines ( similarity > 0.6 ). Rapeseed oil emitted the most particulate matter, soybean oil emitted the most nonmethane hydrocarbons, and both produced the highest PAHs, notably anthracene ( 276.88 μg m − 3 ) and benzo[a]pyrene. Noncarcinogenic risk arose mainly from acrolein, and the lifetime carcinogenic risk (LCR) exceeded 1.0 × 10 − 6 for all cuisines. VOCs contributed 86.3%–94.1% of total cancer risk and PAHs 5.9%–13.7%, the latter dominated by benzo[a]pyrene. Applying the proposed five-level early-warning scheme, high-oil, high-temperature methods (barbecue and Sichuan cuisine) reached the highest warning levels, and occupational workers were consistently classified one to two levels above nearby residents. The results highlight the need for targeted control of key pollutants (e.g., acrolein and 1,3-butadiene, benzo[a]pyrene) and for occupational protection in catering kitchens.
Abstract During voluntary and involuntary spill events, total dissolved gas (TDG) levels may increase, potentially causing gas bubble disease (GBD) in fish. At hydropower plants (HPPs), one approach to mitigate TDG supersaturation is the use of deflectors in spillway design. Ideally, deflector design integrates physical modeling with mathematical or computational approaches; however, such simulations typically require substantial computational resources. This study presents a cellular automata model to estimate TDG levels using hydrodynamic velocity fields simulated in OpenFOAM as input data. The main advantage of this approach is its low computational cost because it can be executed on a personal computer, making it suitable for preliminary studies. In contrast, the simulations conducted for the design of the Colíder HPP spillway deflector required high-performance computing resources, utilizing a cluster with 96 processors.
Abstract Indoor air quality (IAQ) is an often overlooked factor in public health, especially for groups that spend long periods indoors, including firefighters, children in day care, and elderly in long-term care facilities (LTCFs). These populations face heightened exposure to airborne pathogens, chemical irritants, and fine particulate matter. This review synthesizes research from 1990 to 2025, including peer-reviewed studies, technical reports, and government guidelines, to assess IAQ challenges across fire stations, day care centers, and LTCFs. It highlights shared vulnerabilities, setting-specific risks, and opportunities for cross-sector improvement. Across all three environments, inadequate ventilation, the absence of enforceable IAQ standards, and inconsistent use of control technologies contribute to poor air quality. Conventional approaches, such as passive ventilation and high-efficiency particulate air (HEPA) filtration, provide only partial protection, often failing to remove pathogens, volatile organic compounds (VOCs), and ultrafine particles. Mechanical ventilation systems offer more control but are frequently outdated, energy intensive, or limited by air recirculation. Even when buildings meet recommended air changes per hour (ACH), real-world studies show uneven pollutant removal due to airflow patterns, structural obstructions, and occupant movement. These shortcomings disproportionately affect biologically vulnerable groups, underscoring the limits of ventilation alone. Emerging technologies, particularly compressive heating air sterilization technology (CHAST), offer promising alternatives. CHAST systems rapidly inactivate airborne microorganisms, degrade VOCs, and remove particulate matter without generating harmful byproducts. Laboratory and field evidence suggests they can significantly reduce bioburdens across diverse indoor settings. Improving IAQ in high-risk environments requires strategies combining ventilation optimization, continuous monitoring, and active air sterilization technologies. We recommend enforceable IAQ standards for vulnerable population settings, routine IAQ surveillance, and incorporation of advanced pathogen-mitigation technologies into building design and public health preparedness. Future research should develop standardized IAQ performance metrics and integrate IAQ monitoring with infectious disease surveillance. Elevating IAQ to a national and global public health priority is essential for strengthening resilience against future outbreaks.
Abstract Aerobic granular sludge (AGS) is a microbial aggregate utilized in wastewater treatment, often coexisting with flocculent sludge. This study applied a step-feeding strategy in a sequencing batch airlift reactor (SBAR) to treat synthetic sewage. The sludge morphology and nitrogen removal performance were assessed under different feeding steps. The results indicated that both hydraulic shear force and feeding steps significantly contributed to the formation of dense AGS. Under three feeding steps, the average biomass particle size increased from 223 to 245 μm after 25 days, with mixed liquid suspended solids (MLSS) of 5.6 g / L and sludge volume index (SVI) of 50 mL / g . When the influent NH 4 + - N concentration was 43 mg / L , the effluent total nitrogen (TN), NO 3 − - N , and NH 4 + - N decreased to 6.84, 6.80, and 0.0 mg / L , respectively. High-throughput sequencing revealed a substantial enrichment of extracellular polymeric substance (EPS) producing and denitrifying bacteria after 60 days. Variations in nitrogen conversion pathways further demonstrated that three steps of step-feeding effectively enhanced the denitrification capacity of AGS. This study highlights that step-feeding can optimize nitrogen removal while simultaneously enhancing granulation, providing a theoretical basis for advanced nitrogen removal in AGS systems.
